Think it's in 1st but it's in 3rd.

I recently had a lot of trouble adjusting my linkage and got a ton of great advice here on the forum that worked for me. Maybe one of these suggestions will work for you...
http://pantera.infopop.cc/eve/forums/a/tpc/f/6450045562/m/4710044253

I just had an experience with the shift linkage that may apply to others in the future, the little 2"long splined coupling that connects the ZF gear box to the linkage had become so twisted,fatigued that when I broke the nut loose on the turn barrel by resting 1 wrench against the transmission and turning the nut with the other it sheared off. I wasn't able to catch reverse earlier that day and it looks like the last owner was really trying to tighten up the adjustment nuts by the damage to them.. So it appears he was thinking that was the culprit. I also noticed that it appears to be actually 2 peices welded together as when the outer coupler and the inner shaft separated it revealed a perfectly machined hole that the splined end fit into which leads me to believe it was welded from the inside them mill ended or ground smooth on the inside.. Anyway I replaced it for a tidy sum of $183 and it works perfectly now.. Hindsight would lead me to believe that a person could possibly reclock refit, weld, grind then reinstall this peice.

I have your'e solution. I just purchased a pristine 72 Pantera out of an Amish barn in northern Indiana where it had sat under hay for many years! I just drove the car to my home in Tampa (1000 miles; 14 hours) and encountered the first gear problem. Your'e analysis is correct, sometimes it stays in third even though the lever is in first. Easy solution. When you want to go to first, bring the lever to the neutral position and tap it to the left as far as it will go. Do this twice and then move the lever to first. Bingo. It worked great with my car. Hope this helps. Mike Sankey

Sounds like the shifter rod needs some adjustment and the shifetr box needs some grease.