SPR Part #146997 pistons. For a 3.75 stroke crank shaft with a 5.85 rod. Bore is 4.030. They are a -16cc dish. Designed specifically for supercharged, turbo or nitrous applications, thicker crown and lowered ring lands. They are 11:1 compression with a 54cc combustion chamber, zero deck block and a .039 head gasket. Great shape. $250 shipped

Michael

 

what is the stock combustion chamber for LT-1s?

also, your set up it for a 383 stroker right? if so, what needs to be done to the heads for clearance?

thanks,
jeremy

 

Stock combustion chamber size is about 55 or 56 cc's. Yes it is a 383. Nothing needs to be done to the heads or pistons for clearance.

Michael

 

I now have pics available at request.

 

ttt

 

What compression would they be if you had regular deck block, 3.48 stroke crank with 5.7" rods?

Maybe interested. This could help me with my new turbo project.

Thanks

D Moss

ps. These are forged aren't they?

 

Bore : 4.030
stroke : 3.48
Gasket: .039
Gasket Bore : 4.125 (Felpro 1074 I think is the part number)
Head : 56cc (stock)
Deck: .025 (stock I think)
9.3 to 1

Yes they are forged. That is using a 5.85 rod length.
7.4 to 1 with a 5.7 rod.

 

hay thank you for the pics
i will be in touch soon

 

No problem, let me know.

Michael

 

Somebody must need some good pistons.

 

ttt

 

My block is bored .030 over, I can't use them.

Thanks for the info,

D Moss

 

The pistons are 4.030. Not sure why you can't use them. My block is 30 over. Thats why they are 4.030 and not 4.000.

 

ttt

 

up up and away