The stock /6 cam's lift increased to around .410" in 1971 (I think that was the year). So the later cam is actually desirable over the early ones with a .375" lift. And Doug Dutra (Doctor Dodge on www.slantsix.org) sells a pair of 264 duration, .435" lift mechanical lifter cams for use with stock valve springs that you can get with either 112 degree lode separation (lowest RPM range) or 110 lobe separation (medium RPM's, better for a 2 BBL). I have one and it does indeed improve torque up to a 3-4 thousand RPM, which is great for daily driving.
