Cutting the deck is all well and good, but you do not depend on cutting the deck for raising the compression as much as the deck is cut to obtain a good quench figure. That the compression may be raised is secondary to that. Get a clue.
Surely you must realize that the quench distance should be about 0.040". That is done regardless of compression ratio. The chamber volume and dish/dome volume is where the compression ratio is 'made'- NOT the head gasket thickness or deck height, except as a secondary effect to getting the quench right. Get a clue.
A Pontiac 455 can make well over 450 HP on 9.5:1 CR. 450 HP can be done w/9:1. This is NOT a SBC!!! Cutting a Pontiac head 0.060" most certainly WILL do something, AFA compression ratio is concerned. Get a clue.
One more time: The lower compression ratios of the '70s were NOT related to mileage- it was done for emissions. If mileage was a concern, they'd have used different cam timing and a different piston design. And higher compression can potentially get better mileage than lower.
Get a clue!!!