I have a 1987 2855 Contessa powered by a 5.7 liter with vortec heads. The out drive is a OMC geared for a 5.0 liter. I was in need of a drive a few years ago so I purchased this drive because it was advertised a V8 drive. Long story short the drive runs the boat with no problem. I installed my aluminum prop with is a 15 x 15. The boat runs great with this drive it gets up on plain and cruises at anywhere from 18 to 22 mph at half throttle. Here my question the other day I had the boat out the weather got bad and I was rushing back to my marina. I decided to run at full throttle which is a rare but when I got it opened up I noticed that the rpms were just at about 4000. With the old drive WOT rpm was 4800. My question is do I leave it alone. Or do I go to a smaller prop. I saw a 14.75 x 15. Considering it. Before you ask the boat running perfect. Engine is strong and the bottom is clean. I know the gearing in the 5.0 drive is slightly different then the 5.7. Any suggestions? Oh yeah at WOT it did 30 mph speed over ground on the GPS.
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