Dmcneil you should have the later trans. It is a SM465. They changed in 68. You can pull the shift lever out by pushing down on the coller & turning it CCW about an 8th of a turn. Take a big screwdriver & stick it down in the hole & move a rail till all the slots line up. You might see whats wrong or put the lever in & try it again. If you have to pull the cover the reverse gear has to be half way engauged to pull it or put it back on.