Chevy 454 Mark IV short block with 2 piece rear seal from a boat. 4 bolt main block with forged steel crankshaft. I believe it is a reverse rotation since it has the gear drive on it. It is currently stuck and will not rotate. It came out of a boat that had been submerged and when I put it under my shelf over 15 years ago, it would rotate. You’ll have to get everything freed up and it will probably need to be bored .030 over. Includes balancer and flywheel along with gear drive and oil pan. Selling as is with no warranty.