Sounds like a fine well thought out 390 build. Bill and Penelope will both be pleased.
Once had 1974 460 LTD. Installed roller timing set doing 4deg cam advance at same time. That did improve allround performance of otherwise stock motor in heavy LTD.
Using Eagle connecting rods in 460. All this is over kill in Lark for driving/cruising around. Is not a drag racer. But thatz how its turning out. Also with overdrive has OK top end potential inspite of poor-to-no aerodynamics.
BTW - headers are from Australia.