Thanks again for the quick responses on my previous compression thread. Another issue I need to tackle is what size props to outfit a C/R pair of 1999 Yamaha OX66's. I have owned 3 previous sets of Yahama's and never had reason to change out of the stock stainless. However, I would like to explore getting a little more performance (top end) out of these motors. I'm willing to sacrifice a little out of the hole punch. Previously, I've had to trim the motors too far up to get maximum RPM's (5,600) and the front end gets a little squirely; otherwise, RPM's held at about 5,200 or so with engines trimmed half way or so. My mechanic says I should be happy at 5,200 and 56mph. The motors have 25 in shaft and hang off a Whaler-drive on my 25' Whaler Temptation. Any suggestions regarding prop size/pitch for some added performance?