Thanks guys, thats the sort of input I was hoping for. Im now rethinking my RPM capability in hopes of gaining some reliability and cost savings. I want this motor to be reliable, but I want it to kick ass too. I had planned on using a flat tappet cam, the rollers are just too expensive, and I have read that they can fail in boats because of all the idling they do-any truth to that? One thing I know is that I want the cubes that the dart block will offer, in addition to the added benefits it offers over a stock block. This motor will be with me for a long time, as I will use it in successive boats as well. I like the edlebrock RPM heads, they are cheap, and I know they can make decent power. With those heads, do you think this motor will turn 6500 RPM with relative ease? I know that the camshaft and pump setup will have much to do with that. Thanks for all your help.