sit n' low

i've done a search and read that running stock 4.8/5.3 heads on an lq4 would raise the compression between 10.7-11.0 and not flow as well do to the smaller valves. so what if, the 4.8/5.3 heads were ported and polished and had bigger valves? i don't care if the commpression higher, i just want to know if it will still perform well, say mid 12's.
i have a
2x4 scsb
full exhaust, no cats
4.10's
4l60e w/2800 stall
and some more stuff
i also want to run a cam in the 236 112 area