Can anyone recomend what pistons to run in my 4.1? Id like to go 30 over. Does anyone use SBC pistons, or does it raise the comp to much? Forged 4.1 pistons arent cheap so ill probally go with hypers.
If you bore the bock .035" over (4" bore) then you can use SBC pistons. The drawback there is the pin height will be wrong so a different length rod will also be needed unless of course you order custom pistons CHA-CHING! The advantage of the 4" bore is the ring selection is way better. If you can find a set of Buick 3.0 liter rods (6.33") and use an off the shelf 383 SBC blower piston you will be close to correct CR. The final CR would all depend on block deck height and the combustion chamber size on the heads.
If that all sounds like too much work then it is back to stock replacements or forged. I have seen ebay auctions for 4.1L pistons but I have never used them.
Who makes forged pistons for the 4.1s, or do they have to be orderd? Alot of people say hypers are fine, but im afraid to run them underboost. Thanks for the help.
I bought two sets of forged stage 2-- 4.00"-not sure which ones i ll be using-i may have a set up for sale. probably about $400.set anyone know what correct pin height should be?
