Boat motor?

Picked up a boat 71 340 block a couple years ago, at least I think it was a boat block because there were no serial numbers stamped in the block and the dip stick hole had a plug in it. Was just a block and main caps but I put a Muscle Motors 416 forged stroker kit in it and stuffed it in my 71 Duster and man the thing is a beast! Go for it, a lot of those old boat motors were fresh water cooled and even though they seen some use at 4000 rpm they usually didn't have many hours on them.