Just how interchangeable are the 72-80 and 81-92 trucks? I'm getting ready to get moving on my 72 stepside frame off rebuild. I have a 92 d150 as a parts truck and the frame is in much better shape than the 72 d100. I'm thinking of swapping frames. I assume the bolt points are the same. and I know the gas tank location is different. so planning to take the tank out of the cab if I can find a stepside filler neck as well. also, the 72 is a manual and since I can't find a good manual trans to put in and I got my hands on a low mileage 46RH to use on the build. I'll have to go automatic and swap the hard parts from the 92. any help or info on compatible manual trans I could use would also be appreciated. thanks in advance.