what is your opinion this combo?

I think this is more the type of piston that should have been used.
KB373 CHRYSLER 360 6.123 2.75c 2.75cc/Step . >080" quench pad is to be machined to obtain the desired .040 quench - provided the top of the piston is not sitting above the deck already.
At your elevation you could likey run 10.5-11.0:1 CR on pump gas, but 12.80-13.2 no way.