In need of some 273 head education

I'm in the same boat. My 66 Dart needs a rebuild. I am putting together a
Magnum head 318 to run while I rebuild my stock HP273. The high compression in the HP273's are in the pistons not in the heads. But for max.
performance the heads should be ported by someone who knows how. The bore is so small that the heads can't be modified too much by installing larger diameter valves to improve flow. Most parts that you need to rebuild are available through your local parts store. The only hard to find part is the high comp. pistons (which I believe are available through Egge Machine). I am planning a .030 overbore block, .010/.010 crank, 10.5/1 pistons etc. I have a friend who ports Mopar heads professionally and said he could warm up my HP273 heads on the flow bench. I will port match the intake and the factory exhaust manifolds and install a free flowing exhaust. That will be good enough. If I feel I need to hot rod the Dart more I will build a 400+ cube stroker motor and go that route.. Mike