10.5 to 1 pistons

Commando (or "HiPo") engines had a cast-iron 4 bbl intake and special valve covers w/ fins.

You also occasionally see Badger HiPo pistons on ebay. Those and factory HiPo pistons are different for the left and right banks. I don't know about Egge's. One trick racers did was to swap left and right banks to supposedly up performance.

I put a hydraulic cam in my 1965 273, thus oiling is same as later engines. I bought ball & cup pushrods that work with my factory adjustable rockers, for the special 340 TA engine (~1972). Of course you could use later stamped rockers, but why lose the adjust-ability and downgrade.