Good evening everyone
So recently I purchased a 1972 Mustang Mach 1 with a 351 auto FMX trans. So the car has been parked since 1986 and is completely original. The car had a transmission service in 1986 and something got messed up and the car was parked. The problem is the shift pattern for the shifter is completely messed up for the gearshift. So P on the gear shift is drive, D and 2 is reverse, there is no park.

I was hearing something about the shift lever in the trans is set wrong.

Anyone have an idea on what's going on?

Can the lever on the transmission be installed upside down? Sure seems to fit the symptoms.

I know some transmission this can happen. Might be a simple fix. Have a look at the linkage or post a picture.

if i remember right, those transmissions had the shift lever on the transmission "keyed" so it could go on in two positions 180* apart.
try installing the shift lever opposite as it is now, and see what happens.
please report back as to your findings.

Don't know if this will help but here's a pic of the FMX shift lever and associated parts.

My Cyclone has an FMX. All I can say is the suggested fix doesn't take care of the problem, get professional help. Oddly enough, everything including knowledge is focused on the C4 and C6. Whatever you do, do not install a Boss Hog torque converter in it. Mine lasted about 10 miles before internal explosion. If you need a TQ convertor, PM me. Trust me, I found a very good Trans shop that makes billet units. Even worse, I was told there is not 1 FMX but they kinda go by years so finding parts can be a bit specific. Even worse, swapping over to a C6/4 has about as many problems as just fixing the FMX. The good news is there are shops out there that can work on them and if the thing works good, fix the problem you have and don't mess with it. PS, pop the pan and do a filter change if you can. While your at it, take a look at the valve body. My buddy has done the 4/6's, 727s, 350s/400s and says he has never seen something like the FMX valve body. lol. I'm not a trans guy by a long mile so I'll take his word on it..