The ZF transmissions used in F250 and up behind either a 351W or 460 have integral bellhousings in the patterns of those two engines. They will not bolt up to an FE. It was SAID there are adaptors in the following thread, but no link to anyone selling such a thing. Forget the ZF, go for an NV4500. Oh yes, note the Clark being mentioned. Most are 1:1 in high, most are worn out, most are at the bottom of a scrap pile, and all require modifications to an FT flywheel and a host of other minor details.
http://www.ford-trucks.com/forums/88...ml#post7950042
Note there are links in that thread that take you to a company with info/parts/adaptors for the NV4500 into a Ford.