Ed,
In what catalog were you looking?
Rockauto.com's catalog takes some getting used to to, but they list parts by make, mode, year, engine. They separately show the same manifold gasket set for the 1946 Chevrolet 21 and 235 engine.
1946 Chevrolet Truck - by engine After getting used to Rockauto.com's catalog, they are far easier to use that NAPA's catalog, and far more comprehensive and extensive than many other catalogs. Usually, I find a part number/nbrand from Rockauto ad then check that part/price at other vendors. Rockauto ends up being less expensive and much quicker than man other vendors.
Good luck,
