I have a 1982 46 HP with the 8-92's. Top speed is 27 KTS but not getting full RPM either due to a less than honest bottom diver or it seems port side not getting full throttle or both. Was told it was 30KT boat new. Cruise is 20KTS at 1750-1800 RPM.

A similar HP modern engine would give same top end but higher cruise since they can run higher RPM's than a DD at cruise. I would guess a 23-24KT cruise which IMO is plenty fast. If serious fishing I could see the need for higher HP and speeds. Otherwise we are quite happy at 20KTS. Owners preference and needs are the deciding factors.