With an OHC-6 Sprint, you want a properly calibrated carburetor set up FOR THAT ENGINE (displacement, carburetor, compression ratio, camshaft). Try Primatech Motorsports and see if they have any OHC carbs on hand.
The OHC carb is very similar to, but not identical to, the V-8 carb.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching