I have a 7.3 with a bad zf5. i bought a 460 zf5 thats good for cheap. If i can swap the housing i will good to go. is it possible??

 

Yes you can swap front housings easily but you have to setup main shaft and counter shaft bearing preloads which is a bit more involving.

 

crap. how do i do that?? do i need shims??

 

You would need shims unless you got lucky and needed the same thickness as one of the two transmissions you already have. However, the gear ratios are different between gas and diesel, and I think the input shaft as well.

To set pre-load, you would remove all shims, install the bearing races, and with the transmission on end, measure how much freeplay there is in the mainshaft and countershaft and shim that amount plus 0.004" (see pdf attachment).