So here's another thread about selection for my camshaft. I am building a 283 for circletrack motor and am meant to be leaving the enginge stock as equipt from factory! Now obviously nobody does that unless you're really green
The rule that I have to keep with is the 15" of vacume at 800 RPM. Other than that someone will have to do a tear down of the motor and then check grind numbers to check the camshaft.
Here are the two that I am looking at and then I have a few questions.
Comp Dual Energy 12-208-2 Summit Racing Link
Comp XTREME Energy 12-238-2 Summit Racing Link
I am already planning to use Rhoads lifters to help on the idle quality and vacume readings. Here are my questions:
What is your recomendation among those two camshafts? I have to run stock manifolds exaust (center dumps) and intake. I have unmodified 60cc chamberd GM heads and my 283 is not bored. Do you think the vacume will be alright?
The notes on both the camshafts say  Requires machining on cylinder heads. *** does that mean? could they be a little more ambiguious? What will need to be machined?