I've got a Saginaw four speed.They came in Camaro's, monza's vega's, etc. from '66 - '86. They aren't as strong as a Muncie, but don't cost nearly as much either. They are quiet, and very smooth shifting when in good condition.
Here's an
>>>ARTICLE<<< They're getting a little tougher to find lately, but it's an easy swap. I think it should bolt right in for you with the same drive shaft and all. I know it's a direct swap for a stock 3 speed in our trucks. The gearbox in the picture has the Hurst linkage kit made specifically for our trucks equipped with this trans. It puts the shifter far enough forward to use a bench seat.