2bbl conversion for slant six

IIRC the Super Six package may have had another 1/4" of exhaust diameter but no other significant changes. An exhaust upgrade can be beneficial, but isn't mandatory when installing a Super Six. Although any changes to the manifolds will be easier when you have them off already, of course.

If you want a mild exhaust upgrade, the Dutra dual exhaust conversion (now sold by Aussiespeed) is a pretty good street option.