OK looking for this info on searches but can not find, what is the correct piston for the 69 z28. was it TRW L 2210A ???
For the technically correct piston..... This link is to the NHRA approved piston list for the stock classes.
http://www.nhra.com/userfiles/file/NHRAAcceptedProducts.pdf (http://www.nhra.com/userfiles/file/NHRAAcceptedProducts.pdf)
Scroll down to the 302ci engine under the Chevrolet section and it will show the manufacturer and their piston number...it also shows the stock specs for the pistons.
The TRW L2210AF is close but they are machined for the wrong size rings.
I always use the SRP pistons in all of the 302s that we build. Way superior piston over the stock ones. Go on the SRP web site and check them out. They are beautiful. John Allouez Restorations
I belive TRW originally supplied them to GM but they were not exactly the same as the L2210A TRW's you could buy at the speed shop. The speed shop versions have a higher dome on them along with other small differences. The Chevy Power Manual shows P/N: 3946876 as the GM service part.
-Mark.
The original raw forgings were supplied by TRW and finish-machined at Flint V-8; they had forging number 3927172 on the bottom of the dome.
what would a person buy to replace with the most correct for a new DZ motor Joe
The TRW's are not correct and have the wrong ring land. I use J&E which are the NHRA approved pistons for Stock Eliminator. CP is also good. Both make more hp than any other correct 302 11-1 pistons.........and are technically correct 100%. Average hp doing a stock rebuild for our customer base is in the 365-400 range.
Jerry