Yes Albert, we built everything under the KISS principle, you have done a lot to your engine. I am sure that is where the differences are. We plan on trying a 20 x 36 to slow the engine and get more bang for our buck, running a 20 x 28 now as that is what came with the hull, she is new old stock....hull number 14, 26 years old and has only seen water 7 0r 8 times. we will steam few more times with the prop on her to continue to monitor performance.