This is a USED set of GM BBC pistons. These have a. 990 pin dia.
Pistons SBC 4.126" JE 456631 NASCAR ARCA NHRA IHRA Truck MUD UMP IMCA WISSOTA KN
Pistons BBC 4.500" 1.65 ch SRP PN 139482 NHRA IHRA Truck IMCA WISSOTA MUD K&N #1
Pistons BBC 4.442" 1.55 ch CP 4516 NHRA IHRA Truck IMCA WISSOTA MUD K&N
Pistons BBC 4.290" 1.350 CH Speed Pro H880CP +040 NHRA IHRA Truck IMCA WISSOTA
NGK IFR6T11, One Ngk Spark Plug Stock # 4589 High Performance & Racing Parts
JE Pistons Head Gasket GM1010-039; MLS .039 in. 4.540 in. Bore for 396-454 BBC
