Custom ground camshaft, low power

Looks like I lied about header size. I went and measured the circumference of my pipes and the outer diameter is 2.14" So I'm guessing I have 2" pipes. I'm not sure why I was thinking I had 1 5/8 pipes. I have Pro Parts headers that I bought through schumachers. Are these healthy enough for the numbers I'm looking to get?

I did another leakdown test. I didn't calibrate it correctly the first time. I had 20% leakdown on a cold engine. I was told not to pull plugs out of hot aluminum heads or I'd do the test hot. Is there any truth to this? According to the gauge I can have up to 40% leakage and still be in the mild range. 40-60% being moderate, and beyond that extreame. So I should be safe.