Check the manifold bolt pattern. Size 2 carburetor bases have center-to-center spacing of two and eleven/sixteenth inches. Size 3 carburetor bases have center-to-center spacing of two and fifteen/sixteenth inches.

We really like the Carter W-1 (1946-1948 Chevrolet) for size 2 carburetors (mechanical power system).

For size 3 carburetors, Zenith 28AV12, 28BV12; Stromberg BXOV-3, and BXUV-3 work well.

In any case, an EXACT MATCH BY PART NUMBER is desirable.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop