318 complete combo suggestions...

you do not have to deck the block to zero
just to get the quench you want with available gaskets
that said I take cc out of the head and get some more flow by unshrouding the valves
first cc the heads and see what the real cc's are or did you do that and I missed that (most likely forgot)
cheers
Aj has it right
the cam should pick your rpm range
get that nailed down
then build the motor to match
not the other way around ending up with too much compression and too big a cam and starting off on tha

I WROTE THIS EARLIER AND IT DID NOT POST- NO IDEA IF IT STILL FITS IN OR WHERE IT FITS