Crank tabs should be a higher yield material for durability. Something like 4140 pre-hard may be appropriate. Soft mild steel will crush under the fastener washer face and your flexplate will come loose even if the fastener does not turn. Also, if there is room to make the tabs thicker, that would also be a good thing for both tab durability and bolt stretch. Longer grip length (clamping thickness) improves bolted joint durability.

If there is room, I would make a ring with six (or more) holes of whatever thickness (1/4 inch?) adds up to equal a flywheel thickness and use crank bolts for a manual trans flywheel. Sandwich the flexplate between the crank flange and the ring. Gotcha here is I don't know how much room there is to the torque converter?

boltscience.com is a good basic reference for bolted joint design

Last edited by strokersix; 08/21/14 12:59 PM.