How can you tell the diffence between a 5.0L 305 V8 compared to a 5.7L 350 V8?

Question

Im looking into buying a 1986 Tuned Port Injected IROC Camaro and i was told it Had a 350 small block in it. But i checked the Vin number and it said it was a 305. I dnt know if they had the engine changed out or told me a lie, but i was wondering if there is things I can look for to tell the difference.

Answer 1

First thing is ask a simple question like, is it the stock engine?
Have you hopped it up any?
By changing the crankshaft, you can raise your c.i. number--back in the day, a 307 was a 283 with a 350 crank in it, so, you know.
After that, check the serial numbers on the block and heads.

Answer 2

1

Answer 3

here is a list of all 1986 engines look at the vin or block #


Code Year CID HP BBL Appl
C7D 1986 305 150 4 Roch E4ME carb.
C7H 1986 305 150 4 Roch E4ME carb.
DDD 1986 305 camaro auto
DDS 1986 305 camaro auto
DDY 1986 305 camaro
Vehicle Identification Number Example: 1G1AP87H4CN100000
First Digit Nation of Origin: 1=USA, 2=Canada
Second Digit Division: G=General Motors
Third Digit: 1=Chevrolet, 7=GM of Canada('83-'88)
Fourth Digit: A=non-passive, B=automatic belts, C=inflatable restraint, F=Coupe
Fifth Digit Model: P=Camaro Coupe or Z28, S=Berlinetta
Six & Seven Digits Body Style: 87=Sport Coupe/Camaro,
Eigth Digit Engine: See Engine Codes
Ninth Digit is Check digit
Tenth Digit Year: C=82, D=83, E=84, F=85, G=86
Eleventh Digit Production Plant: N=Norwood,Ohio, L=Van Nuys
Last Six Digits increase by one with each car built at each plant


Casting Years CID HP Main Notes
10051184 1986-up 350 N/A 4 1 piece rear main seal. BOWTIE
10051184 1986-up 350 4 Bowtie, 4.00"-4.155" bores, 1 or 2-piece rear seal
10054727 1986-up 350 2/4 one piece rear seal, some "Made in Canada"
10066036 350 2/4 Target Master/Goodwrench crate
14011064 1982-86 350 N\A 4 High Tin
14094766 1986-up 305 2 One-piece rear seal
10046164 1986 305

Answer 4

There is no way of telling the difference between chevy 305/350 engine by sight. The only way to find out is by the #'s on the rear of the engine. You wrote that you checked the cars VIN # (eight digit # is "F") then the car came orginally with a 305 TPI engine, but who's to say the owner did not install a 350 later on? Ask the owner for proof. 1985-1990 Chevy Camaro IROC-Z that had a 5.7 engine did not come with 5 speed manual, they all came with automatic.

Answer 5

There is no way of telling by the naked eye, small block Chevy's all look the same other than the 400 witch had a different harmonic balancer. If the block is 1988 or newer it will be stamped on the back of the block 5.0 or 5.7 neer the bell housing. But on the carberated models the only true way to tell is by running the numbers stamped into the block. People always try to pass 305s for 350s.

Answer 6

i had the same problem with my 87' trans am, i bought it from a lady who told me that it was a 350 with 283 heads on it but when i bout it and looked the catylist on the hood and the vin told me it was a 305, there is no way to tell from the naked eye and if anyone ever tells you that a 350 is a big block they dont know anything about a car, the only way to tell is to check the serial number on the block and if you still cant tell then you would have to get someone to check the bore on the cylinders, a 305 has a 3.74 in bore and the 350 has a 4 in bore and they have the same 3.48 in stroke, so good luck with finding out

Answer 7

Don't listen to Monty the man a 350 is not, will not, and will never be a big block motor so just ignore him. I would go with the first person check the vin on all the motor parts to see if they are 305 or 350

Answer 8

If you checked the Vin number on the motor and was told it was a 305 then it is.

If you didn't check the motor Vin, look behind the vale cover on the drivers side. You should see a stamp on the block with numbers. Have them numbers ran if they aren't the ones you already had ran. Sometimes it will tell you under these Vin numbers if it's a 5.0 or a 5.7.

If there aren't any numbers on the block, look beside motor mounts on the block, but the numbers should be behind the vale cover.

Answer 9

This is wild! I had an 86 caprice with a 305, it is stamped tword the front of the engine near the intake, although it may be hard to see and covered in grease.

The Small Block Chevy has a machined pad in front of the passenger side cylinder head. Often hidden by the alterator.

Big Block Chevy: Above timing chain cover (not that it is, but for reference)

You could also try this: http://www.nastyz28.com/gm-chevy-codes/chevy-engine-codes-suffix-2.php if you find the suffix code.

Answer 10

Chevy 288's a good guy. The way to distinguish the difference between a small and big block is exhaust port separation. There will be a spark plug behind every exhaust port with out the double exhaust port separation of a small block. In other words any two spark plugs will never sit side by side as all small blocks do. Or if you see porcelain facing porcelain.