What Jeff said. Additionally, make sure you get the heads cc'd. There can be quite a bit of variance on chamber size. I have a set of 781's that cc'd at 124 cc's. This would drop you to around 8.5:1 CR. To get back up, you may have to mill heads and deck block, and/or run a thinner head gasket.

If you are going to run the 2.25 valves on a 4.25 bore, it woudl be a good idea to bore notch the top of the cylinders to unshroud the valves.

I put in the forged domed pistons from speedpro :) over 9:1 compression

Still farting in the wind put a blower on it.
Go with rm builder youll be pissn in the wind :)

Yea, I have never ran anything with a blower, the thought has entered my mind many times. I am maxed out on HP and speed with my current setup. Maybe I should just be happy and leave it alone for a while. Damn "speed bug" got me and its hard to shake :drink:
Bob really knows what he is doing on engine/cam design.

Is that good or bad? Doesn't sound like the reputation I've always heard he's been known for.

It all worked out, but it took a real long time, between hard to get in contact with, long shipping, and him ruling out reversion and blaming my new head gasket and intake manifold gaskets, basically doing a top end job on a rebuilt motor after asking if reversion was a possibility.
I went with him bc i read so much about him knowing marine cams to avoid reversion.

Bob's customer service is unbelievable and he's always easy to get ahold of. If you had to weld in 10" extensions then you've got other issues and you're crutching the problem with your long pipes. What's your base timing, port volume on your heads, what intake, what's your idle speed, how'd you lash your valves, how's the rocker geometry, you running silent choice? There are many thing's that contribute to reversion and in my experience Bob's cams aren't one of them. I've got a dozen or so customers running Bob's valve train's and ZERO reversion issues.