advancing the cam doesn't do too much. The HP stays pretty much the same and the torque increases from 283@4000 to 286@4000. Not enough to bother. Thats with stock 4 barrel intake and a 550 carb with stock manifolds and exhaust.
That is only the effect on peak torque of cam advance so that is not the way to help the the OP's 'low end grunt' question.... peak torque is not what counts at low RPM's..
BTW, OP, 10.5 with the stock heads and original pop-up pistons is not likely. You need to measure the head's combustion chambers and know you head gasket thickness, but for production stuff, high 9's is more realistic for those pistons, and it will be lower for the Egge replacement L2222's. But that ain't awful either.. not like you will have a smog era 318 low compression!
Certainly it will have more low end grunt than with the flat tops. Probably will feel something like a stock late 60's 318 off idle, judging from the DCR results being in the low 7's. So it depends on what you are happy with...