When we ran our engine on the dyno it was with collector headers to get the exhaust out of the dyno cell. I guessed the dyno headers had to be worth 20-40 hp. I have always ran zoomies . We have several nostalgia cars in our group with modern scoops, carb(s) and collector headers. If it were up to me it would be stack or hat injection or blower, any fuel , no intake scoops and zoomies only. The lack of a delay box and model year largely makes a nostalgia car with our group. Oh, and your dial must be 4.99 or quicker.