I don't even remember what the muncie shifter was like. I would think the linkage. The first thing I would check is all the rod bushings and the alignment adjustment if it was a Hurst shifter. If that stuff was worn or out of alignment I would get the bushings and tighten everything back up to see if that fixed it. If it did not I would check to make sure that the console is in the right location? How much clearance do you have in reverse first and third at the front of the console? If you have a lot of room in the front and the shifter is in the exact spot it should be maybe the console is not. Highly unlikely but I have aligned consoles to shifters before.