Cam question for '66 GTO with '72 400
I have been thinking about purchasing a cam for my GTO, but have no idea where to even start. There is so much information out there about intake/exhaust duration and lift, valve springs, lifters, etc. and I am just totally lost. I love the sound of a lumpy/lopey cam, but don't want to go so aggressive that the idle is overly rough, and since this is solely a street cruiser, I would prefer a cam with more low to mid range power/torque over a high RPM screamer. Is this a possibility without other extensive modification?
The engine is out of a '72 Trans Am and other than adding a new Holley 650 carb, headers, and 2.5" exhaust, everything is stock (to my knowledge). It has an auto trans. The engine was in the car when I bought it. I am unsure of compression ratio, gearing, and other important things like that, but it seems like companies like Crower or Comp Cams make hydraulic, flat-tappet cams that will basically fit any Pontiac V8 from 265-455 from the '50s to the '80s...?
What should I be looking for, and do you have any recommendations? I apologize if this is way too broad of a question.