Chiphead,
I have the M4F cam. To start with my cam is not set straight up as they say. I have the cam advanced 4 degrees with a cam key, I think I used the std chevy V8 keys you can get from Jegs or the local speed shop. It sucks a steady 21 inches of vac at about 650 rpm but will go lower. As for valve settings - the cam card says to set hot at .014 and .016, however on mine it sounds like the hammers of hell and I can visualize the valve stems turning into mushrooms. So I re set a few times and the 235 appears now to like .012 & .014 on what they call regular fuel. The tighter the valve settings will move the power band up and along with it the rpm. If you go the other way and leave at .014 & .016 the engine will have lots of low end torque and will better match a stock 4.11:1 rear or a 3.90:1. Both these valve settings will have associated timing and plug color changes. Your engine will run cooler with more valve seat time; example .014 to .016 (.016 setting will allow more heat transfer to the cooling system) Good Luck. I ended up with a 165 therm and it runs a steady 170 or less even on the hot muggy days.
