new flexplate with spacer and ARP bolts for all 6 bolt LS style engines when using 4L80E, turbo 400 or any early transmission with 11.5" bolt circle torque converter.
Will not work with converters with 10.5" bolt circle that most 350, 700R4 & powerglides originally came with.
This is what you will need to swap a 4L80E in place of any other transmission.