[Steeveedee]

I've seen plenty of big blocks with 2 barrel carbs, I worked for a Chevy dealer on and off from 1970-1972. I'd suspect that the cam would be different between the two barrel and 4 barrel, but have no proof. I've even seen 421 Pontiacs with a 2 barrel. Our body shop manager had a '68 Star Chief that got 20 MPG on the open road with that setup. Beasts like that had tons of torque, and even the big cars had tall axles.