On the 83+ the inspection cover is raised even higher where the shifters are. That is the first year the five speed was offered on the 4X series. The transmission tunnel was lower on the pre 73. I used one from a 73-78 range in my 68 when I switched to a four speed. I putting a five speed on my 79 since it the easiest year of the FJ40s I have. My 73 would have been my second choice because the tunnel higher than previous years. It also has a arch in the torque tube where the rear driveline goes under it. Considering using a 82 frame since crossmember will bolt in and the five speed skid plate uses the same threaded nuts as a 82 with a four speed.