Thanks for all of the input on upgrading power from a 496HO. I've since been doing quite a bit of research on this. And I think that the comments here about upgrading to forged internals is probably a must. I don't want to have to worry about whether the motor internals will handle the extra power from a Raylar kit or a Whipple kit. And when you start factoring in the labor to re-build the internals, you might as well just spend a little more to upgrade to the 525. Plus, I don't like the idea of tearing the motor apart. Anytime you start doing that it just seems like it's never the same again. So my thinking is that if you are going to upgrade to 525hp, might as well spend the money once, buy the blue motor, and get it right. Not sure how to get hold of Mel Riggs or El Indio. If anyone can help me with that, that would be great. I have spoken with Shipyard Marine in Green Bay (they are a Donzi dealer), and the service guy there sounded pretty knowledgeable. One thing I'd be curious about. With the 2008 Donzi 27ZR that I have, I pull about 3,400 rpm's on takeoff until plan, and 5,050 at WOT. I top out at 72 mph. I'm running a 28 pitch Bravo 1 with 1.65 gear ratio. I think my prop and gearing a pretty good, since i'm getting what I think is the most out of this boat. Assuming I go with a 525, I know I'll get more top speed, but what about rpm's while getting on plane. I'd like to see a little quicker plane time. I would think that with the extra hp and torque, and assuming a re-prop, I should be able to turn a little more rpm while getting on plane. Any thoughts on this?