I have an ‘82 Sea Ray Amberjack 255. Upgraded the original 330/BBC with center riser 4” exhaust, stroked up .25” in the last rebuild including a mild cam and low profile open plenum intake to keep it under the floor.

The motor has noticeably more power now but still seems to be held back by the TR drive as the original 330 topping out at about 3500-4000rpm. Would finding a TRS be worth it? Would the TRS 1.5:1 ratio drop the motor rpm too low for this type of boat? It’s not a performance boat and has a lot of extra weight added AC/genset/inverter and batteries etc. The boat gets on plane easily with a full load but just seems to be dragging an anchor so to speak. It will top out at about 36-38mph. I think it could be more efficient cruising on long runs with a LU that doesn’t use a ceiling fan as a prop?

The Konrad is the obvious choice but would a TRS LU be a cheap alternative?

-BL

The current TR prop is 15x21p, I had it cleaned up and cut down in diameter to about 14" and some cup added. I couldn't imagine why a prop needed to be that big, didn't seem to hurt it as it doesn't slip at all. I think 4 blade SS would be much better.