Hey everyone,
first off just like to say this site is an awsome place to get info for my GTA. I own a 87 GTA that i bought in 97, drove it from B.C. to NFLD (canada) blew the 700 tranny on the way! and It has been in my garage for the past 5 years getting alot of tlc. To make a long story short, i need to know if my gta has a 350 or a 305. according to the VIN its a 305. After reading alot of the posts here im thinking it may be a 350, cause i heard the 305 came with the 5-speed and mines got the auto tranny. I was told it was a 350 when i bought it, but i was only 18 at the time and i didnt really look into it and took the dealers word for it ...(those guys can be slick) anyway, i know the car has had the rear end replaced cause there's drums in the back. hoping someone can tell me if theres anywhere on the engine itself where i can find a code or some other kind of ID to confirm if its a 305 or 350 before i start buying parts for a 305 and it turns out to be a 350.
Thanks in advance.

 

305s got either trans, 350s only got the auto. run the casting number off the block at www.mortec.com

 

Just because the you have drum brakes doesnt mean it has a different rear end. There were still drums in 87 right? Maybe not, I dont know but I have an 89 RS and I have drum. Anyway the casting number is on the back of the block behind the intake manifold near the drivers side heads. Its pretty hard to see but if you move a few things you will see it. Another way of telling is to pull the valve covers and get the head casting numbers either way look and let me know what the last 3 numbers on either casting and I will tell you what you have. Good Luck.

 

Drums were still standard into 91 possibly 92. Rear disc's were available as an upgrade though.

 

If you can locate the service parts label in the glove box or where ever, look at the RPO codes, look for a code in the middle of the list that starts with an "L". It should say LB9 or L98. The next code after it should be MD8.If it says neither, then look for the code in the "b" section it might say B2L, if it says L98 or B2L then it's a 350.

 

The VIN does not lie. Does the car have t-tops? The '87 is the hardest to verify genuine GTA unless you have the RPO sticker in the glovie still. If so Y84 says GTA. I don't recall any of the GTA's having drum brakes in the back, none of mine ever did, but purpotedly the '91 and '92 years had the option for AL drum rear, not sure of that though. The 87 I had, had the 350 and no TTops. I've been told that the 350 w/ TTops began in '88 but I'm not decided yet on that.
A few things to check, dash pocket should say GTA in gold or a gold bird or something in gold. Not Trans Am. No vents in the fenders if it's a real GTA. Ultima seats (4th gen seats) should be in there if it's a GTA. Steering wheel should have a gold bird on it, center rear section should be a gold bird, your wheels, if opriginal, should be gold w/o the nub at the hub. Only year made this way. IIRC the PONTIAC on the front light should be in gold as well. The vin must begin w/ 1G2FW, this is for T/A and GTA cars.
Unless you have your RPO codes (SPI label) it's iffy. If you have TTops, that may be why you have the 305. Only way to make sure of the motor is to run the casting number, and w/o the rpo's you 'd have to write to Pontiac to verify GTA authentication.

 

thanks for all the help guys ... looks like its a 305 in there, not that it really matters to me, the 305 is fine, just wanted to be sure what I was working with. As for if its a real GTA. Looks that way to me, it checks out with the VIN and its got all the emblems and stuff that it should have, (I took the body ones off when i had it painted) Here's a few pics of her if ya wanna have a look .. I'll post more when i gut the interior, I'm gonna clean that up first. . Thanks again.
(sorry if the pics are kinda big)

 

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dash

 

engine

 

thats some unique seats you have there

 

Tell me about it ... there just some cheap covers i put on cause i'm changing the color of the interior from that ugly brown to black, just temp till i get the seat covers from hawks, already got the carpet, 1 thing at a time.

 

that gauge display is different looking. Was that just in GTA's? I have a 89 and 90 Formula and there gauges look alot diff than that.

 

Far as I know it was just in GTA's, And I think it was only the 87's that had that set up. I only say that though cause the 88 GTA's that Iv'e seen had a different set up with the radio controls on the steering wheel.