Fastest Duster on stockish suspension?
Whatever is easier for you to get parts for. If you have a bunch of low deck stuff and a 400 block. There you go. Tell everyone its just a 383! Small blocks fit nicely in an A body. Point is you goal really wouldn’t be taxing any of them BB/low deck/SB. Availability, probably biggest factor. If you can run a split mono in the class. It gives you options. SS springs work fine, but the idea of them was to control the tire with the spring, not the shock. They are pretty stiff.