I've been running a saginaw 4 speed in my '69 Camaro for the last 15 years or so. It has to have at least 100k that I put on it, because it is my daily driver. The trans has been sitting on the end of a 350 since bought freshly rebuilt for great price. Only abused occaisionally, but the 4:11s in the back keep it working hard all the time.

If I remember correctly, the position of my old Mr. Gasket vertical gate shifter changed location slightly when I was forced to replace the existing muncie creating some problems with the shifter rod clearances and the placement of the shifter boot.

Allthough I have no idea if mine is the same as the one you've got, my saginaw has served me well.