it's better to get the proper ratio for your engine drive package. they're set up to work together. i think gear ratio's are set up to match engines. very from that and you'll have trouble getting it to work proper. yer engine needs to be able to achive wot. not to much rpm, or to little.
You will gain low end torque on your propshaft, and you will lose some top end speed in the example you give because WOT RPM will be too high. Theoretically both will change by the 11.5% difference in the numeric gear change, 11.5% more torque on the shaft at peak values (11.5% lower shaft RPM) and 11.5% more RPM at WOT, same max horsepower at the shaft. You would need to go up in propeller pitch to match, then your overall performance should be somewhat comparable. That's not to say that the combo will be as good of a match for your engine and hull, but mathematically you can compensate with propeller pitch.
Umm and dont argue with them to much, sometime's they get a bit cranky... Welcome by the way..
