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You have a very similar combo to what i have in the works for racing this upcoming season.
I too have the Dougs headers.
I had them on my 360 with eddies that was 10 to 1
For now going to live with them on my 418 with same eddie heads.
Collector wise, i went from 3 to 3.5 inch collectors on a W5 motor i had that went well into the 9’s, and saw absolutely nothing making the swap