833 belhousing adapter ring

Why doesn't anyone make a adapter ring to go from a regular 833 4 spd with the 4.35 dia. bering retainer to the 5.125 O.D. bell housing? I'd like to put a non O.D. 4 speed behind my 71 slant. I can find O.D. bell housings all day for the slant but no regular 4 speed ones. Anyone on here with a lathe interested in turning out a few?