Get a early 70 water pump housing with the lower hose on the right side. Then get a radiator with the lower hose on the right side. Opens up a lot of room.
Swap a plug hole to hole and a plug wire see if it changes. Change out the intake gasket, need a good seal to trouble shoot further. Where in Colorado?
Run the 452s just a 906 with hardened seats. Are you set on running the 509 cam? Tour going to need a good converter with it. The 284--484 would sound snotty and run fine with flat tops.