But aren’t the intake manifolds different from the 383 to 440?452s came on 400s as well as 440s. I'm not sure if they were cast early enough for the 383. But as John said, there is no "B" or "RB" cylinder head. They all interchange. There are also some 200 series castings like 203, 206 and the like. The standard open chamber heads are all about the same.....although the 906 does flow a tad better. With the money that it will take to get a pair in shape, you will probably want to look at some new offerings in aluminum.