This engine has either had a Six Pack or a tunnel ram on it after I rebuilt it in 1979 the first time. It has been in a 70 GTX, 70 Polara 2Dr, 69 Dart, 70 Cuda, 110" FED and this 75 Duster. It's almost ready to light up with this 850 Pro Form. I had to cut a wedge of metal out of the linkage arm...