so I purchased a car that is badged as an IROC. I decoded the VIN and it says it came with a 2.8 v6 (clearly not an IROC since they had V8's). Now I know the engine will have the VIN on it but whoever swapped it did one H**L of a job and made it look like it belongs in the car. I looked at the engine and could not see the VIN. Do I have to move the alternator or something to see. An help is appreciated.

 

Look at the VIN tag on the drivers side, very front of the dash,,,something like 18 letters and numbers...that will tell you what the car originally is/was...compare to your title, those numbers should be EXACT or take the effer to court and collect your money.

 

Those are but like I said if I decode that it says it came with a v6 not a v8. Can't be an iroc like what the badges say because they only came in v8. I need help figuring out the engine not the car.

 

What is the 8th letter or number on the VIN?
Off the top of my head, 8, F, E are V8's, I think S is a V6

BTW, one the deck in front of the head (forget which one) there is a stamp pad where the numbers should be, provided the block hadn't been decked, they should be present.

And yes, the Alternator could be blocking your view.

 

thanks, will have to try and check this weekend.

 

I had the same problem with mine. It was badged with Iroc and the externals on the car didn't match what i was looking at so i looked it up. The car was actually an iroc but the engine didn't look like it was stock. The stamping number on mine was on the top of the block right behind the driver side head on the flange where the bellhousing bolts up. I pulled those numbers and found out that my block was from a 1972 C-10. It was still a 350 but not the original engine. So look there and see what you can find. That is where i found my casting numbers on my block. Let us know what you find if anything at all

 

will do. I actually first questioned it, before decoding the vin, when I was talking to some of the other tech's at my work. I realized the vacuum setup was like the 350 and the person I got it from said it was a 305 which doesn't match up with the setup under the hood. im hoping it is a 350 and not a 305 with the vacuum lines set up like the 350. luckily between the other techs and the info we have (since I work for chevy lol) I can figure almost everything out. sadly since its an 88 some info we don't have.

 

Yea that is very true. If you can't find the casting numbers it will be very hard o just look at it and decipher between the a 350 and 305 without the casting numbers. The only other way i know is to take the head off and measure the bore. As far as the block itself the only difference is the bore and stroke and maybe the motor mount placement. A 305 bore is a 3 1/2 inch bore and a 350 is a 4 inch bore. So that could be another way to tell what you have. The vacuum setup could be different with the same engine but a different setup so the vacuum setup wouldn't be the best way to try to figure out what you have to my knowledge.

 

The VIN is stamped in several places on the car. Under the T-top seals is the most common. If the body is original, there should be VIN stickers on the backs of the fenders and rear bumper. Check the build sheet tucked under the carpet/seats or the production code tag mounted in the rear cargo box/glove box

If the car looks unmolested with a V8 and the VIN says V6, it might be hot and retagged. Check the VIN's rivets. They are not common round studs, but more a star

 

i didn't know that. Do all the 'F' bodies have a build plan under the carpet or seats?

 

The engine codes are on the pad on front pass side of block right in front of the head. The alt. may be in the way.

This will be the pre fix, vin and suffix codes. Use brake parts cleaner/wd-40/carb cleaner etc and an old tooth brush/detail brush, etc and a rag to clean the area real well as the numbers are not stamped very deep and tends to fill up with dirt and grease over time.

The casting number is on rear of block, behind driver's side head on top of the flange that transmission bolts up too.