If you want to keep the 3 speed/column shift, look into installing the 1970's Saginaw 3 speed with the synchronized 1st. gear. That makes 1st. a traffic gear instead of having to come to a full stop, and the earlier column shift linkage can be tweaked to work with the later model transmission. You might need to alter the driveshaft length, as I believe the Saginaw is a bit longer that the Muncie. The Saginaw is a bolt-in swap for the Muncie, as far as bellhousing bolt pattern and clutch splines are concerned.
Jerry

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