I have Doug's D452 headers on my Savoy with Indy EZ heads and they fit perfect and the coating is still nice. The angle plugs on the Indy heads might provide extra clearance but my Firecore wires fit perfect as well not even close to the 2" tubes.
The only fit issue I had was the grease fitting on the pitman arm was dragging on the bottom of the pipes.
I had to remove the fitting and all was well
My combo also has an 11" 143 tooth wheel and a steel clutch can I had to notch the lip for tube clearance.
Gus