HH56 wrote:
Look at the gear select linkage on the drivers side when in park. In park the old lever and rod setup will have the end of the lever on the side of the transmission almost flat or at most 5 degrees or so up from horizontal. With a bad adjustment or if slop developed the lever end could fall down or even go below horizontal so the linkage was trying to push in a straight line.

The new lever has the setscrew in a different position so when in park the lever end is around 15 or 20 degrees up from horizontal. The long rod connecting to the bellcrank was also changed in length to accommodate the new lever position. While it might be difficult to connect and even more so to adjust, it could be possible there is a mismatch of parts. If that were the case even though the dash sector label might indicate one gear the transmission might be in another.

One other issue that has developed is the lever on the inside of the case the outer lever and shaft connects with is held by a setscrew. The inside lever is pot metal and threads for the setscrew can strip allowing slop to develop. The inside lever moves the manual valve in the valve body and any slop could also result in the driver indicator reading one gear while the trans is in another or even halfway between gears. Slop can usually be determined if you can wiggle the operator lever more than a very few degrees before it seems to drop into a detent. If you can then disconnect the long rod at the trans lever and try to move the lever manually. In any position other than park more than an eighth of an inch or so movement at the rod end would indicate excessive play inside.