I've got an 88 d100 with a 904 trany that is crapping out on me. I like to replace it with a 727, but I don't know how much is involved. For one I believe there are "short tail" and a "long tail" 727? I know were I can get a low mileage "short tail", I just don't want to get it and then find out I should have gotten a "long tail"? As far as the drive shaft I'm guessing it would be best to go to the local pick-n-pull and get one that was originally attached to a 727? What about the trany mount and cross member? I also read somewhere that the trany oil lines fittings are different?

 

If you have a short wheel base truck? you could use it. Trans mount & cross member should be the same Most trucks that use a short tail are two piece drive shafts. Drive shaft will have to be custom. I think the shortie has a bolt on flange ? not the standard slip yoke. You would be better off just go to local Pick & Pull find a van or PU with a 727 and get every thing you need