Basically its everything you would think it is, from the pedal assembly, to the flywheel, but the only thing im not sure of is if your transfer case is the same as the zf-5.
Oh yeah, you probably want the zf-5 for your 351. I have had a few 302's with the m5od and have had great luck with them, but for the larger engine (especially if you run more power then stock) you probably want the stouter transmission.
actually, there also is the bw 4407,which came with the zf5 i swapped into my truck. however, the original bw 1356 bolts right to it, linkage and all, this is what i did for the time being. once i have the time and cash to get a new fixed yoke rear driveshaft, the much beefier looking 4407 will be reunited with the zf. by the way, i went from a 300 m5od to a 351 zf, both driveshafts fit right in with the 1356, no changes necessary. same with the transmission/t-case crossmember. since my truck always was a 5 speed, i cant help you with the pedals and stuff. hope this helps.