Just picked up my M20 from being rebuilt and Hurst shifter mounted.
Asked Ed, Muncie guy, about your situation and if a Saginaw tail can be mounted on Muncie main case and he said no way but if it did, nothing would line up inside......I then explained the issue of your shifter sticking way up high and he said common problem! Wrong mounting plate, the plate between the shifter mechanism and the tranny. He said people used the wrong ones or made something goofy. Saginaw mounting plate used on a Muncie tranny, Hurst mounting plate used with a Muncie shifter, etc, etc...
Ol' ED has been rebuilding Muncie's and Saginaws since the mid 60's (according to him) He's quite the old hotrodder.