I have a big block crank here in the shop that is 84 lbs! Solid rod pins, full counterweights, solid mains, etc. That is about 20 lbs more than they usually are.

The circle track guy that I work with has a 434 SBC circle track motor with a 37 lb crank in it. That motor has Ti rods, light pistons, tiny pins, the whole nine yards. It is a motor that he leases to big buck boys when they need to win a race.