Early slant 6 Four speed bellhousing

I agree with what 65Dartman said about differences in mounting location for the "Z" bar ballstud. Further, I don't think you want the 64-6? iron bellhousing as it does NOT have the dual bolt pattern for both the three and four speed transmissions. I believe the only bell housing with both patterns in the later aluminum housing from OD 4 spd cars with the larger bearing retaining hole. I have one of those if confirmed that's what you need.