Piston question..

[Boatally Insane]

I have two different sets of pistons and am trying to decide which ones to use in my low budget build..


I have a Gen IV block with a forged crank and rods. The crank, rods, and pistons look like new, but the block's cooling passages have a LOT of rust and the cylinder walls need some attention. :ack2:

The pistons have 6262976 stamped on the top of them.
I've found a LOT of info on these.
From Dennis Moore's book.

Piston Assembly. std. 1971 454-cid
RPO LS6 Forged Aluminum w/9.0:1 compression
Pressed-pin design (ident. 3994031, 3999295, 6262972
or 6269362-3)

They also cross to a speed pro L2399F



I also have a Gen VI block that appears to have been a fairly fresh rebuild. The pistons and cylinder walls look like new but it has a cast crank / rods AND a spun a rod bearing. :willy_nilly:

The pistons have 6262977 stamped on the top.
ALL I've found on these is from Dennis Moore's book...

Piston Assembly. std. High-limit
1971 454-cid RPO LS6 Forged Aluminum w/9.0:1
compression. Pressed-pin design (ident. 3994032
6262973 or 6269364)

I can't seem to find ANY other reference to these pistons....anywhere...

Any ideas?

Also, any idea why the speed pro L2399F isn't listed for use in a Gen VI block?

I'd like to use the Gen IV forged rotating assembly and my Gen VI block (with a rear seal adapter of course) .....but which pistons...?..


Thanks,

Doug