Marine 383s

[rolling_Thunder]

The problem with reverse rotation engines is that they have some specific components that make it unsuitable for use in a vehicle. The cam is ground backwards, the distributor is backwards and the crank is often different. The rear main bearing surface on some engines had serrations in the crank to pull oil in away from the seal. If that crank is spun the other way, it pushes oil toward the seal and increases the risk of a leak.

Ran into this on a 440 once... someone used a marine crank from a reverse rotation engine... you'll NEVER get the rear-main seal to not leak...