Ok, so flat tops with 2 relief and 64 CC chamber, your are up somewhere around 10. Could 10.25 to 1... Could be 9.5, just a stab in the dark until you know exact data on the piston and the crush of the head gasket.The pistons were flat with the 1 (or 2?) dimple(s) on them. I'm assuming standard pistons.
Car can idle, run fine...revs fine without load. Heck, if I feather it enough, she screams past 100mph. It's just when I come to a stop and punch it...it falls on its face, or stalls.
Going to put a roller cam in, since I don't know what this cam is. Not going to try to figure out what it is.
What you do know is your timing is going to be around 4 to 8 before TDC as a starting point.
Your description of drivability with the current setup is exactly what you will have with the HEI using no advance.
Until you can properly curve your distributor and tune to your engine, no changes will happen even with perfect fuel quality and delivery.
As far as Cam... If you are high compression and running a Mother Thumper your base line vacuum will be around 12 to 15 inches. And your blow by will most likely be high.
So don't get to concerned on exact cam at this point. It's more important to baseline, and then work from there.
If your base tune is bad, then in reality, not much else matters.