I know there are some that won't like what I did to fix the shifter on my "67 ss12. Instead of removing the transmission to take the shifter out, I just took my angle grinder and made the opening in the frame, where the shifter sticks up, a little larger. I removed the 4 bolts, pulled the shifter out and sure enough,, things had been jammed out of whack. I took a screwdriver, stepped on the clutch, click, click, and things were back to normal. I put the shifter back in and all gears worked fine again.
Thank You all that offered suggestions.