compression vs. compression ratio

yeah...so what i'm thinking....is if i have in _______area for a compression reading, as opposed to a _____area reading, then it's still low compression.....with the blanks being, for example, 90-130# and 180-200#, or something like that

the engine was "built" few miles ago....i was told 50.....i doubt it was that recent...probably more like 500
but the motor IS cleeean

and i don't think 452 heads came on a 72 400, did they??

my boss at work said i can check the intake mounting face on the heads to see if they've been milled, but i don't know what i'm looking for