318 Magnum

I agree with LX. And to elaborate the LA 318 have the pistons way down in the hole that's why he said to mill the heads to get the compression up. A cam as big as your looking at will work fine with 4:10 gears and a 4spd but not with a 8 to 1 compression engine and stock exh. manifolds. That's where the problem lies. That's why you need a smaller cam. Otherwise you'll just give up 40-50 lbs of torque to gain 10 hp. (est.) That's not a good trade off. Those heads flow real good in stock form and porting usually looses some velocity so with the smaller cam and only 318 cubic inches stock would probably be better. JMHO The absolute biggest cam I'd consider is the 268. If you gain much from porting it won't be allot. The Lunati cams also have a bigger split between the intake and exhaust so with stock exhaust manifolds I believe they'll make more power than their Comp Cams counterparts. Again JMHO.