[motorhead99]

im trying to find out what size pistons go in a 99gt. the haynes manual says something about coded red 1, coded blue 2, and coded yellow 3. i have no clue which one to go off of. i need to order new ones and even summit cant narrow it down enough for me to know

[Dolbs4082]

I thought in my chiltons book it said something like 3.56? on the bore and 3.55 on the stroke? i may be completely wrong on this tho. who knows haha

[motorhead99]

the ranges i get are 3.5526-3.5531, 3.5531-3.5536, and 3.5536-3.5541. this is so confusing. ive done a lot of work on this car but ive never gone this deep into it. ive got everything to do it, i just need the pistons and rings

[Dolbs4082]

well, if i were you, i'd take it to a machinest and have them hone the block for you, then figure out from him the size of bore its got. that way your new pistons are "hone matched"

[I8ACMRO]

I think the bore is 3.552 and the stroke is 3.543

[motorhead99]

well even when it gets re-honed, its not gonna take a lot out. the only thing close is just the 3.552 on summit. im not totally sure though.

[Dolbs4082]

Originally Posted by I8ACMRO I think the bore is 3.552 and the stroke is 3.543

i think my stroke is 3.75 tho? haha

[motorhead99]

Originally Posted by I8ACMRO I think the bore is 3.552 and the stroke is 3.543

cool. thats what im lookin at now. thanks guys. thats what i needed.

[limited]

Originally Posted by motorhead99 the ranges i get are 3.5526-3.5531, 3.5531-3.5536, and 3.5536-3.5541. this is so confusing. ive done a lot of work on this car but ive never gone this deep into it. ive got everything to do it, i just need the pistons and rings

well you should go forged pistons and with those they require a .0035+ ptw clearance which is more than stock so the block will need to be honed to fit anyway

[99 BLUE V6]

Originally Posted by motorhead99 the ranges i get are 3.5526-3.5531, 3.5531-3.5536, and 3.5536-3.5541. this is so confusing. ive done a lot of work on this car but ive never gone this deep into it. ive got everything to do it, i just need the pistons and rings

A 99 should be ready for a .020 over bore. But 3.552 is what our books show at work for STD.You do plan on having it honed right!

[motorhead99]

Originally Posted by 99 BLUE V6 A 99 should be ready for a .020 over bore. But 3.552 is what our books show at work for STD.You do plan on having it honed right!

i have a buddy of mine who's dad has a shop in VA. he's gonna take a look at it and make sure its all jollied up for me. i guess ill find out from there. there was a piece broken off one of my pistons. i ran it down and cant see or feel any grooves at all in the cylinder. im just trying to figure out where this piece decided to run off to. i guess ill fid out tomorrow when i flip it over and start pulling connecting rods. thanks guys. ill update this if i have any more questions about these pistons

[Dolbs4082]

that peice prolly broke off during a predetonation in the chamber. then rattled around in there until it was small enough to go threw your heads and out your exhaust. thats what mine did anyways! haha