I ordered a custom Comp Cam from Keith Craft Racing and the specs seem pretty crazy and radical. What do you guys think: Solid roller Duration 258I/276E at .050 lift .672 lift I/E -.022 lash=.650 lift lobe separation 110 degrees This is for 331 NA with 13:1 compression, AFR 205's, max RPM of 7000, and everything else race. Is that the new thing nowadays to have a huge exhaust duration with a lower intake duration??? I was thinking around 260/260 would be about right, but I don't know cams that well.
Did you mention any nitrous? Because the exhaust duration looks like a nitrous cam.... Yet, the lobe centers are tight.... I"m a converted Pontiac man, so I'm a little curious also. Keith and company knows their stuff... Hmmmmmmmmm....... Call Comp Cams tech line and bounce it off them. And do it a few times. Different guys telling you the same thing is good. Three different guys telling you three different things from the same company isn't...
Same cam I used in a 351w 14:1 compression, max 6800 RPM. It worked pretty good... Then I changed to a Cam Research cam (guy does ONLY Ford cams!) and it picked up some RPM, MPH, torque and best of all it was cheaper than the Comp cam that I had before. New one is around 274 duration and .700" lift. The one you have will work just fine. Hope you like to wing it up around 7500-8000 RPM though.
Not really, the whole reason I ordered a custom cam was so that I could get the most out of the engine with a max rpm of 7000 and I wanted to limit the lift to between .600 to .650. I told the guy I wanted to keep the rpm's less than 7000. I don't think my internals can take that kind of revving. They also gave me a .672 lift with .022 lash to make it .650 lift, but it all seems too radical to me. I don't want to break the block on the first pass. I'd rather go slower and be more reliable. I'm also going to probably have piston to valve clearance problems now.
All good forged rotating assembly, racing bearings, rings, etc. Block has been bored, torque plate honed, align honed with girdle torqued in-place, zero decked, stroker clearanced, cleaned and prepped. The weak link is the stock '72 block. Hope it holds up.