Hi, I just recently purchased an '88 Firebird Formula. I was told when I purchased the car that it had a 350 in it, but stupid me never checked it out before I bought it. According to the vin, it only had a 305, but I wanted to know for sure.

It is a TBI setup (I know there was no 350 TBI in an 88 firebird), but I pulled the air filter part off and found a part number for the intake. It said this:
WI (or W1) GM
14102182

According to a guy from the AACF newsgroup it is from either a '91 or '92. Now the alternator also looks like it has been swapped. So it looks like the engine COULD have been swapped for a TBI 350... but I don't know for sure... can anyone help? I spent 45 mins with a flashlight and a mirror looking around the engine, and all I was able to see was a partial number behind the engine on the pass side by the Transmission and all I could see was 1609(then maybe a 3?)
Does this help anyone? I really would like to know what it has. Thanks!

 

 

For your information most sellers claim a 305 car is a 350 which they are not. Check the Vin for engine type and forget about what parts on on it. Your lack of knowledge of the car cost you.
All stock 3rd gen cars with a 350 had a TPI induction.

 

Yeah I know that a stock 350 was TPI (after I bought it) but the intake is new and the alternator looks like it also has been replaced, so I was just trying to see if it indeed was swapped out with a 350 tbi... the quest continues.

 

Like they said, stop playing games and get the numbers off the block. Thats the only real way to know. I could take a 305 and replace everything attached to it with 350 parts, and it'd still be a 305.

 

you can tell by the sound, a 305 never sounds as deep as a 350 even with the most noisiest mufflers.

if you can get a sound clip of the engine idling and reving, I'm sure I'm not the only one here who can call it!

 

dude just get the casting # and look it up on the internet... and if your not sure take the heads off and measure the diameter of the bore of the cylinder.... sometimes it says "5.7L" next to the casting # and the bore for a 350 is 4.000"

BTW junkyarddog.... you CANNOT tell the difference between a 305 and a 350 by sound... that is THE STUPIDEST THING I HAVE EVER heard

 

Your quest should be over. Look at the picture I posted. It shows you clearly where to look on your block. It will have "5.0" or "5.7" stamped right on it.

 

There is no way to accurately gauge displacement by the sound of a motor.

 

Well, I couldn't see any numbers on the back of the engine, but I took off the A/C compressor ans looked on the little plate between there and the block, and found my partial VIN, therefore it is infact the original 305. Thanks everyone.

 

Good that you found out. If you belived 99 44/100% of the sellers, GM did not make a 305 in a IROC or Z28.

 

I won't argue about the sound thing. it's pointless.

I am not an idiot, however. Some people can't tell the difference between a Jensen and a Clarion stereo, and maybee some people can't hear the same tones as others.

Ask yourself, would there be any confusion if a 5.0 stang pulled up, and a 5.0 camaro was running and you couldn't see these two cars? it's only a difference of 3 cubic inches, why don't they sound the same? it's not the displacement that you hear, it's the charactaristic harmonics of that motor. If you've seen and heard enough different motors, it is easy to hear the differences, especially stock. there is no way to accuratly judge displacement by sound alone. I have never heard a 305 and 350 TPI or TBI that sounded similar, usually the 350 has the stronger note from idle to WOT.

 

the 302 and the 305 are made by 2 different comanies they will sound different... the same as a mopar, a ford, and a GM will not sound the same... a 305 and a 350 will sound exactly the same or so close that you CANNOT tell by just listening... the cam makes the idle sound differently... so since he found out he has a 305 lets just end this debate on weather you can tell the difference between a 305 and a 350 by sound... becuase the simple fact is that YOU CANT

 

I've bought a few camaros and helped my buddies buy a few and isnt that the truth they are always telling you its a 350 and that no gm didnt put a 305 in a Iroc or Z thats hilarious. i have two Irocs with original motors, hell one with tbi!