Stock TTA Piston Part Number

[10 sec TTa]

Anyone know what the stock TTA Piston casting number should be?

Thanks,
Scott

[1badTTA]

25535089
Pretty sure that is the correct nubmer, kinda hard to read the 5th digit though.

If interested I have 5 good used stock bore pistons with 36,000 miles on them sitting in my garage.

[1badTTA]

CID YEAR FACTORY HP
231 89 Turbo V-6
JE 181379
That is what NHRA lists as the stock replacement piston for the TTA's

You won't find any pistons available from GM, I tried. They are out of both stock bore and over bore in all the sizes. HTH

[10 sec TTa]

Here's the thing. There is a guy selling a TTA Crate motor on Ebay, but the pistons don't look to be dished deep enough. The guy thinks it's a TTA motor, but I think it has the buick pistons in it. He said the pistons are 25535089 castings. Anyone know what that casting number is? They are in a crate motor SG1. I have a crate motor SG1 already but I am almost positive the one I have has the buick pistons in it. I think that many people just assume that the TTA's were the only thing to use the SG1 blocks. The stock buick casting number that I found on my original buick pistons didn't match the 25535089 either so I thought maybe buick used a different piston in the late crate motors. Anyone have any other ideas?

Thanks
Scott

[1badTTA]

Well if the crate engine he is selling has the 25535089 pistons in it, it is for a TTA. I have one of my original TTA pistons sitting in front of me and that is what I am reading the number off of.

I found the auction on ebay and you can't tell from the pics how deep the dish is. It does state that the crank has cross drilled mains and if with the 5089 pistons, I would say for sure it is a TTA engine. HTH

[10 sec TTa]

I wrote down the number you posted. The number his has is 25531068. Sorry for the confussion.... Anyone know what this casting number is and where is the casting number located on the piston? Can it be read with the piston in the bore?
Thanks,
Scott Heidinger

[1badTTA]

It is cast on the inside of the piston on the skirt. It may be rather hard to see with the rod in the way, but with the engine rotated just right, it should be possible.

Other casting marks on mine are
71772
HEPOLITE
22166A

BUICK
25535089
413P

[FHW]

My '87 Turbo Pistons are numbered 25531068.
The dish depth measures .245
The rumor that sg1 blocks are all turbo ta motors is not correct.
I just installed an sg1 motor in my '87 GN and it was ordered as a replacement '86-'87 turbo motor.
It had the 25531068 pistons and the crank shaft was not cross drilled.
HTH

[davege]

I noticed a part number on the short block crate of 25527476 in one of the Ebay photos. I then looked up the number for a 89 TTA 3.8 short block in my January 1992 parts book and found it to be 24500190. I then checked this morning with my Pontiac parts guy on the two numbers. His parts system shows the number of 25527476, being for a 86-87 Regal. The number I found in my parts book, shows as the short block for a 89 tta in the GM Parts system. He also checked for me and found the 25527476 number was never a replacement number for the 89 TTA short block. So what is being sold is not a 89 TTA block.

- Dave

[10 sec TTa]

I had asked this individual for some pics and to measure the depth of the dish of the pistons. He never sent me either. He tried to sell the short block on this board before he put it on ebay. He also wouldn't give me a straight answer about shipping or export taxes coming from Canada. I see he didn't meet his reserve price on ebay, but what's worse is he doesn't know what he is selling. Thanks for all the replies, it helped keep me wasting more money on parts that won't work on the TTA.

[webleyaz]

When I bought my TTA in '96 it had a broken crankshaft. Being clueless at the time I installed a pair of GN pistons in the rear two holes and drove it until last Nov. when the wastegate hose came off and blew the head gasket. I cannot see the difference in the two pistons even sitting next to each other. The dishes on the two pistons are .190 and .170 making them 25.33cc for the TTa and 22.7cc for the GN. 2.47cc. About the size of a small marble. Tough to see when spread out across the floor of a piston dish. I just looked at them minutes ago and they all had part #25535089. And all say BUICK on them. I can't explain it.