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How much does a 350 rebuild cost?


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#1 wildweaselmi

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Posted 06 June 2011 - 08:35 AM

Looking to see how much does it cost if I get a car that needs an engine rebuild and since 350 is the common engine in most GM vehicles I am focusing on that model.

#2 shadowmac

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Posted 06 June 2011 - 10:18 AM

The cost of a rebuild can vary quite a 'bit depending on what you need to replace, the level of machining work that needs to be done, and obviously, who you bring it to and how much they charge.

A typical rebuild will consist of cleaning all the parts to be re-used (including the engine block, cylinder heads, crankshaft, and connecting rods, which is usually done by the machinist). Milling the cylinder heads, boring the block, and sometimes turning the crank under, to ensure consistency, and a good fit well within tolerances. Usually it will also be left to a machinist to install all the bearings and plugs in the engine, as well as pressing the pins into the piston, and installing the piston on the rods. A lot of this can be done by a good mechanic as well, as long as they have the proper tools and machines to do so.
The rest of the assembly can usually be done with a basic garage setup, just so long as the builder knows how to properly lubricate the parts, torque everything down, adjust the valve lash, and if in charge of the first firing and break in, properly adjust timing, check pressures, and look for any problems.
But to address your original question of how much it costs....

Rebuild kits for Chevy 350 engines range anywhere from $400 to $800 for basic setups, and should include most, if not every part you'll need to replace (bearings, plugs, seals, new pistons, rings, cam, etc.) These kits do not include things like water pumps, alternators, belts, manifolds, etc. If you are building for higher performance, expect to pay at least in the $1,500 - $3,000 range and up, depending on how much power you want to make.

Basic cleaning and machining by the machinist usually doesn't exceed $300 - $500, but if the machinist finds other things wrong than the basics, expect to pay more. Re-seating valves, and rebuilding cylinder heads can typically run you anywhere from $200 - $600, not including parts........just to give you an example.
Anyway, to bring this ramble to a close, on the low end, I would expect to pay at least $1,500 - $2,000 for a decent rebuild, and on the high end (as long as your talking basic, not performance), expect around $3,000 and up. Keep in mind, again, this does not usually include parts like water pumps, belts, fluids, etc. And you'll also have to keep in mind extra expenses like removal and re-installation of the engine, and some places also charge for the disassembly of the engine as well.

Your best bet is to talk with a few local, reputable mechanics and/or machinists, and they could give you a better idea of the service they offer, the prices they charge (as a lot of that varies by region, etc.), and what sort of turnaround you'd be looking at.

#3 wildweaselmi

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Posted 13 June 2011 - 09:06 AM

Any suggestions on a place in Michigan that sell rebuilt motors?

#4 shadowmac

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Posted 13 June 2011 - 09:27 AM

I see you live in Grand Blanc Michigan and two performance speed shops can rebuild an engine for you
EVI
Total Mayhem

OR you could buy a rebuilt motor from one of these places
BluePrint Engines
Mondello Performance Products
HiPerformer
Precision Engines

OR search for a used engine
automotix

#5 shadowmac

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Posted 13 June 2011 - 02:13 PM

Stay away from any olds engine newer than 76.

Oldsmobile 350

Produced from 1968-1980, the Rocket 350 was entirely different from the other GM divisions' 350's. It used a 4.057 in (103.0 mm) bore and Oldsmobile small-block standard 3.385 in (86.0 mm) stroke for 350 cu in (5.7 L). 1968-1974 350s were painted gold; 1975-1976 350s were metallic blue like the 455; 1977-1980 models were painted GM Corporate Blue. The "Rocket" name disappeared from the air cleaner decal in 1975, the same year that the catalytic converter was added to the emission control systems. Output ranged from 160-325 hp (119-242 kW). The early Oldsmobile 350s made from 1968-1976 are more desirable engines with heavy castings, beefier crankshafts, and better flowing heads. The later 1977 thru 1980 350 had the "lightweight" castings, including a thinner block with large "windows" in the main bearing bulkheads, crack-prone head castings which were actually manufactured by Pontiac Motor Division (castings are marked "PMD"; these heads were also used on the 260), and a lightened crankshaft.

Gasoline blocks produced in 1977 and later years were cast with holes in the main bearing web area, hence the term windowed mains, or windowed main blocks. Some 1977 gas blocks have solid mains. All diesel blocks have solid mains. These windowed blocks are less strong in this area, but that should not affect street applications.



#6 wildweaselmi

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Posted 13 June 2011 - 02:32 PM

Is it better to upgrade to a 455 versus sticking with a 350?

#7 shadowmac

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Posted 13 June 2011 - 02:35 PM

Is it better to upgrade to a 455 versus sticking with a 350?

The small blocks have a number of design advantages. One, the bore size on a 350 is not much smaller than that on a 455, and the bore size on a 403 is much bigger than a 455's bore. That means these two small blocks can use valves as big or bigger than a 455 can, and with less valve shrouding for the 403 than the 455. Usually, the most restrictive item in the whole intake port of an engine is the valves; this means that a small block Olds engine's heads should be able to flow about as many cfm as a big-block Olds, and ultimately the maximum horsepower you can get from any engine depends only on the airflow. This means that: Gasp! A 350 or 403 Olds should be able to make as much or more horsepower than a 455, albeit at a higher rpm.

Want more? Okay, here goes. The 455 has a longer stroke, meaning that more horsepower is wasted in internal friction, rubbing the pistons up and down through that longer stroke; other things being equal, then, the small-blocks should return better gas mileage, even if built to the same peak horsepower as a 455. The rod length/stroke ratio is bigger for a small block than a 455; this means more piston rod angularity for a 455, meaning still more friction with the cylinder walls, and also a lower redline before the connecting rods break from the strain (lower rod/stroke ratios put more strain on the piston rods by accelerating the piston in a more jerky fashion).

Still more? Okay. The small block is lighter, so your Olds will be slightly less nose-heavy and will handle better. Also, your Olds is more likely to already have a 350 in it - surely Olds sold more 350 powered cars than 455's!

It seems that Chevy 350 engines routinely exceed 350 hp in totally streetable engines, and often get nearer the 400 hp mark with good cylinder heads. I can't see why the same power levels shouldn't be achieved with an Olds 350 or 403! The rpm capability seems to be there, with a shorter stroke and better rod/stroke ratio than the Chevy 350; all it would take is getting the heads to flow well enough, and then getting the rest of the combo right. Unless you're driving a full-size Olds that really needs the extra torque of a 455, or a drag-race oriented car, I would think that 400 honest hp from a small block would be enough for most folks who drive mainly on the street.

#8 wildweaselmi

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Posted 13 June 2011 - 02:40 PM

Wow, that's a lot of information. So if you stick with a 350, can you mix the internal parts from one year to the other? How can you tell what will work? It seems if it came out of a 350 it would fit in another 350 as long as it is the same make (Chevy, Olds, Pontiac, etc..)

#9 shadowmac

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Posted 13 June 2011 - 02:41 PM

Wow, that's a lot of information. So if you stick with a 350, can you mix the internal parts from one year to the other? How can you tell what will work? It seems if it came out of a 350 it would fit in another 350 as long as it is the same make (Chevy, Olds, Pontiac, etc..)

The crank, understanding your cost constraints, the best small block Olds crank is the forged unit from the 64-67 330 motors. This will drop into a 350, as main and rod journals are the same size (as is stroke). You will need to rebalance and you'll need to use an early (64-67) flywheel/flexplate due to the crank flange bolt pattern.

With the exception of the W-31s, all Olds small blocks used dished pistons. The high compression pistons used a "shallower" dish than the low compression pistons. This is actually a good design, as the ideal combustion chamber is a sphere. The Olds dished pistons come a lot closer to approximating this sphere than most motors with domed pistons.

Interesting side note: In a period test of the 1970 W-31 in Hot Rod Magazine, they pointed out that the oversquare Olds 350 has the best bore/stroke ratio of any GM 350 motor, with the result that there should be a lot of potential in this motor.

Number 5 heads were used on the W-31s. These heads were used on all 350s of that vintage, with only the addition of the larger (2.00" intake, 1.625" exhaust) valves from the big block. You can have your heads machined to incorporate these larger valves.

#10 wildweaselmi

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Posted 13 June 2011 - 02:45 PM

You are responding rather quickly. How can I tell what an engine came out of?

#11 shadowmac

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Posted 13 June 2011 - 02:46 PM

You are responding rather quickly. How can I tell what an engine came out of?

I could say the same thing about you :)
  • A big block measures 14" between the heads at the manifold base.
  • Facing the front of the engine, at the top surface of the timing chain area, to the left of the oil fill tube, there is a code about 1.5" high followed by the casting number. A letter indicates a big block, a number indicates a small block.
  • Big blocks have a little hump in that area, whereas the small blocks are flat the whole way across.


































































ID/CodeYear(s)CIDCasting NumberNotes
A'65425381917??, 3865251st year, big cars.
B'65400389298442 only, one year only.
D'66 - '67425389244Big-car engine. Toro is different internally.
E'66 - '67400390925442 engine [VERY rare].
F'68 - '70455396021Common big block. Stick type F (sans serif).
F'70 - '72455396021Common big block. Serif type F. Two vertical and a base serif.
Fa'72 - '76455396021Very common big block. Marine also (L VIN derivative).
G'68 - '69400396026442/Vista/etc. engine.
L'76455231788Motorhome, marine and irrigation. GM made motorhomes from '73-8, maybe in all? Casting number appears as "231 [tiny 'L'] 788" on the block.


Look for the casting number and letter on the horizontal shelf right behind the water pump, just to the [driver's] right of the oil pressure sensor. The casting numbers are usually about ¾" - 1" tall, and the ID/Code is usually a bit larger, a little over an inch, and covered with schmutz. The most common block will be the standard 455: "396021 F" or "396021 Fa". The "a", as in Fa, is actually an upper case A, but about ¼ as big as the F, and subscript to the F [set lower]. Also, on the 231788L block, the "L" is the same size as most of the rest of the digits, whereas the numberal "7" is noticeably smaller.



400's were bronze in color, most 425's and early 455's (1968, 1969) were red, while Toronado 425's and later 455's were blue. However, since engine color may have been changed, use this as supporting evidence only.



The VIN derivative stamping or engine unit number on the left most side of the block, on the driver's side, just below the cylinder head, toward the front. The pad is part of the engine and will indicate the year of manufacture, but that is usually rusted beyond recognition, and it can be changed by restamping. If the engine was replaced under warranty, the pad may be blank. Rubbing alcohol and Q-tips help to remove the grime and grit from the stamping.



The VIN derivative on 68-up blocks doesn't tie directly to the type of car it was installed in (unless you have some way to unambiguously trace the last six digits of the VIN), however it _can_ provide some indirect evidence. If the production plant (third place in the VIN derivative) was one at which no 442s were built (KC, for example), then it obviously isn't a 442 motor. Of couse, you have no way of knowing for sure that the heads were originally installed on that block or not.



1964-67 V-8 Engine:

Code is stamped on the right cylinder head. Unfortunately, this only applies to what was originally the driver's side head. This code consists of a prefix letter (330 V8=T(1964-65) or W(1966-67), 400 V8 = V), then a production sequence number, followed by a suffix code letter (L = Low compression, E = 2-bbl export, G = High compression, H = 4-bbl export). A 2-letter code on the oil filler tube identified the engine.



1968-later V-8 Engine

Have the last six digits of the VIN number, the year of the block, and the assembly plant stamped on the driver's side of the block below the cylinder head. A 2-letter code on the oil filler tube identified the engine.



You can use the VIN derivative number to ID the year. For 1968 and up blocks, this number is located on a pad just below the cylinder head on the front left side of the engine. This number will be stamped on a machined pad on the front driver's side of the block, just below the deck surface. Typically it will be covered with a power steering bracket or something, below the number one spark plug location.



This number should take the form of "35Mxxxxxx" where:

3 = Oldsmobile division.

5 = year of manufacture (8=68, 9=69, 0=70, ..., 4=74, 5=75, 6=76, etc.).

M = location of manufacture (M = Lansing, B=Baltimore, X = Kansas City, Z = Fremont, CA, etc).

xxxxxx = last six digits of VIN of car that motor originally came in (original car's sequential production number).



The letter indicating factory must match the letter in the sixth position of the car's VIN (it should also, of course, match the factory indication on the body data plate - in other words, for a Lansing-built car, the sixth place in the VIN would be an "M", the body data plate should indicate "LAN", and the third place in the engine ID should also be an "M").



Some blocks, before 1977, have their ID cast above the right hand center freeze plug, eg. D for 425, F for 455. Olds didn't cast the displacement into the side of the blocks until they went to the light weight design in 1977. The 1977 and newer blocks will have the cubic inches cast in large raised numbers right above the right hand center freeze plug, eg. 403. The 307 will be in liters (5L), and a diesel engine will have the letters "DX" on it. The engine VIN letter will also be cast into the side of the block. Note that the 260 blocks sometimed have the last 3 digits of the casting number cast there, "355", which is rather misleading.



From the factory, the oil filler tube had a sticker containing two letters which indicated components (carb, etc), model application (Cutlass, 88, etc), and other configuration items (timing, CA approved, etc).


#12 shadowmac

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Posted 13 June 2011 - 03:15 PM

  • A small block measures 12" between the heads at the manifold base.
  • Facing the front of the engine, at the top surface of the timing chain area, to the left of the oil fill tube, there is a code about 1.5" high followed by the casting number. A letter indicates a big block, a number indicates a small block.
  • Big blocks have a little hump in that area, whereas the small blocks have a completely flat shelf.
  • Small blocks from 1977 onward will have the CID or liters cast in large numbers right above the center core plug. The engine VIN number will also be cast onto the side of the block.


























































































































ID/Code Year(s) CID Casting Number Notes
1 '64-'66 330 381917 45° cam bank angle.
1A '64-'66 330 381917 45° cam bank angle.
2 '68-'76 350 381917 none
2 '68-'70 350 395558 none
3 '66-'67 330 394417 39° cam bank angle.
4 ? ? ? none
5 '73,'74 350 395558 none
2A '75-'81 260 ? Solid main webs for 2A's only? At least for '76.
2B ??-'81 260 557751 Windowed main webs. Windowed main webs for 2B's only?
3A '79 350 ? none
3B '77-'80 350 557752 none
4A '77 403 557265,553990,554990 Solid main webs possibly for these three casting numbers.
4B '77-'79 403 557265 Windowed main webs always.
?? '85 307 556607 none
5A '81- 307 3161 none
D3 ?? 350 7582 Diesel

From the outside they don't look different at all because the 260, 307, 330, 350, and 403 are all the same basic block. But externally the distributor, valve covers, water pump, front cover, oil pan, carb, etc are the same.



Some blocks, before 1977, have their ID cast above the right hand center freeze plug, eg. D for 425, F for 455. Olds didn't cast the displacement into the side of the blocks until they went to the light weight design in 1977. The 1977 and newer blocks will have the cubic inches cast in large raised numbers right above the right hand center freeze plug, eg. 403. The 307 will be in liters (5L), and a diesel engine will have the letters "DX" on it. The engine VIN letter will also be cast into the side of the block. Note that the 260 blocks sometimes have the last 3 digits of the casting number cast there, "355", which is rather misleading.



The VIN derivative stamping or engine unit number on the left most side of the block, on the driver's side, just below the cylinder head, toward the front. The pad is part of the engine and will indicate the year of manufacture, but that is usually rusted beyond recognition, and it can be changed by restamping. If the engine was replaced under warranty, the pad may be blank. Rubbing alcohol and Q-tips help to remove the grime and grit from the stamping.



Service or replacement blocks will not have any stamping on the pad.



The VIN derivative on 68-up blocks doesn't tie directly to the type of car it was installed in (unless you have some way to unambiguously trace the last six digits of the VIN), however it _can_ provide some indirect evidence. If the production plant (third place in the VIN derivative) was one at which no 442s were built (KC, for example), then it obviously isn't a 442 motor. Of couse, you have no way of knowing for sure that the heads were originally installed on that block or not.



1964-67 V-8 Engine:

Code is stamped on the right cylinder head. Unfortunately, this only applies to what was originally the driver's side head. This code consists of a prefix letter (330 V8=T(1964-65) or W(1966-67), 400 V8 = V), then a production sequence number, followed by a suffix code letter (L = Low compression, E = 2-bbl export, G = High compression, H = 4-bbl export). A 2-letter code on the oil filler tube identified the engine.



1968-later V-8 Engine

Have the last six digits of the VIN number, the year of the block, and the assembly plant stamped on the driver's side of the block below the cylinder head. A 2-letter code on the oil filler tube identified the engine.



You can use the VIN derivative number to ID the year. For 1968 and up blocks, this number is located on a pad just below the cylinder head on the front left side of the engine. This number will be stamped on a machined pad on the front driver's side of the block, just below the deck surface. Typically it will be covered with a power steering bracket or something, below the number one spark plug location.



This number should take the form of "35Mxxxxxx" where:

3 = Oldsmobile division.

5 = year of manufacture (8=68, 9=69, 0=70, ..., 4=74, 5=75, 6=76, etc.).

M = location of manufacture (M = Lansing, B=Baltimore, X = Kansas City, Z = Fremont, CA, etc).

xxxxxx = last six digits of VIN of car that motor originally came in (original car's sequential production number).



The letter indicating factory must match the letter in the sixth position of the car's VIN (it should also, of course, match the factory indication on the body data plate - in other words, for a Lansing-built car, the sixth place in the VIN would be an "M", the body data plate should indicate "LAN", and the third place in the engine ID should also be an "M").



The oil filler tube is stamped with a number that indicates the year and engine unit number. So, 2724927 would break down as follows:

2 = 1972.

724927 = engine unit number.



From the factory, the oil filler tube had a sticker containing two letters which indicated components (carb, etc), model application (Cutlass, 88, etc), and other configuration items (timing, CA approved, etc).



Here are detailed VIN derivative numbers for different engines.



To reiterate from above, pre-1968 engines had an engine unit number stamped on to the machined pad at the front of the RH head. Starting in 1968, the VIN derivative (or engine unit number) of the engine's original car was stamped onto the vertical machined pad on the left side of the block, at the front, just under the head- block interface. It might look like "38M203456", where:



3= Oldsmobile, GM's 3rd division [1=Chevy, 2=Pontiac, 4=Buick, etc.]

8= year of issue last digit, like on oil fill tube [8=1968, 0=1970...]

M= build plant [1, E, G, M, R, or Z; see below], and 203456= the last 6 digits of the original car's VIN.


#13 wildweaselmi

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Posted 13 June 2011 - 03:46 PM

Someone mentioned that you want a 4bolt main because its more durable if you have some horsepower behind it but I don't see any 4bolt main olds 350's, any idea why?

#14 shadowmac

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Posted 13 June 2011 - 03:48 PM

Someone mentioned that you want a 4bolt main because its more durable if you have some horsepower behind it but I don't see any 4bolt main olds 350's, any idea why?

Except for experimental and ultra-exotic [Mondello, Dave Smith Engineering, etc.] custom setups, there is no such thing as an Olds 4-bolt block or main caps [455 or 350, etc.]. There were never any made.

Some other notes.

Lifter Sizes
All engines 1968 and up, (all 455's, 400's, 403's, 350's, 307's, 260's), use the same lifter bank angle of 39°. All 455's and most small blocks [all but late 7A head 307s] use 0.842" diameter lifters. Most pre 1968 engines use 0.842", but set on a 45° bank angle. Some pre 1968 engines used larger 0.921" lifters and a 45° cam bank angle, notably 442 and Toronado engines. 1967 330's used a 39° cam bank angle and larger lifters.

So to summarize,
if it's not a D block, use the following:
E and before blocks: 45 degree CBA, 0.842" lifters.
F and after blocks: 39 degree CBA, 0.921" lifters.

if it is a D block,
39 degree CBA = WITH drill spot on the vertical rib @ RH end of block casting # shelf. Not too deep, just a conical valley. 0.921 [large] lifters. Came in Toro/StarFire/442, maybe Jetstar1.
45 degree CBA = No drill spot. Small [0.842] lifters, same as '68-up motors.

Or use this summary,

Before 1968, use this chart:
330 #1 coded block (64-67 ALL were 45 degree and had .841" lifters)
400 #B coded block (65 only 442, 45 degree and had .841" lifters)
400 #E coded block (66-67 442 39 degree and had .921" lifters)
425 #A coded block (65 only, 45 degree and had .841" lifters)
425 #D coded block (66-67 NON - Toro all were 45 degree and had .841" lifters)
425 #D coded block (66-67 Toro all were 39 degree and had .921" lifters

1968 and after, all are 39° and 0.841" lifters:
350 #2 coded block (68-7? ALL were 39 degree and had .841" lifters)
400 #G coded block (68-69 442, 39 degree and had .841" lifters)
455 #F coded block (68-76 ALL 39 degree and had .841" lifters)
And all 260, 307 and later 350 blocks.

NOTE: The cam must be ground to match the block's cam bank angle. That cam will then work in any Olds engine with the same bank angle, but will NOT work in blocks with the other bank angle. Either lifter diameter can be used with either cam, just get lifters to match the block. Which brings up two important differences: the 0.921" lifters are rather more costly, at about $100 a set vs. $35 a set for the more common units, and the larger lifters require shorter pushrods. Also, some cam manufacturers no longer offer cams in the 45° form. Contact Engle for custom cams, as they grind all Mondello's cams.

You can NOT swap cams between the 45 and the 39 degree blocks. They will fit, BUT the cam timing events will NOT be as advertised. By degreeing the cam you will be able to figure all the specs out using a 39 degree cam in a 45 degree block. Those using a 45 degree engine should call the cam manufacturer to have them grind it for that engine. Will only cost a couple dollars more. Big lifters were only used in the 66-67 engines. Toro and 442. 425's with big lifters are only Toro and will guarantee you a 39 degree block. They have become very difficult to find the lifters and when you do they will not be cheap. Usually around $9.00 per lifter. The other .841 lifter is common, and will run usually less than half the price of the big ones.

Oversize Lifter Bores
With any block, watch out for the 'O' stamp on the lifter bore boss, indicating a 0.010" oversize lifter. Either Oldsmobile would only have stock 0.010" over replacements or THERE ARE NONE AVAILABLE. Which means you either get to sleeve the lifter bore (difficult and expen$ive), or scrap the block, or, re-use that old lifter. Resleeving the lifter bore is not fun.

#15 wildweaselmi

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Posted 13 June 2011 - 06:51 PM

I noticed that the majority of your responses are based around Oldsmobile engines/motors. I'm more of a Chevelle guy so is it the same or similar for Chevy's?





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