welcome to the site bambam! you didn't specify which engine you'd want, i'm assuming you'd go with a mid 90's 7.3 id take a look and compare the 460 gas and 7.3 diesel mounts and other engine related parts out of the mid 90's trucks since they made them both work in the same truck, and i know the 460 was available back in the 70's so there must be some evolution of parts there that you can work with as far as the engine mounts that would make it pratically a bolt in procces up front. the tricky part would be the trans and possibly the 4x4 (if you are going the route) will the 7.3 and late 460 bolt to the same bell housing? are you going manual or auto? are you going with or without the intercooler?
I love the late 70's Fords, my Dad got a '79 F-250 super cab long bed 2 wheel drive with a 460 and auto tranny back when i was 7 years old, in a short time i wanted that truck or one like it. So i got the truck you see in my signature, basicly the modern interpretation of my dad's truck but with 4 wheel drive.
let us know what you are working with. Do you have the truck already? ask us as many questions as you need. this sounds like a fun project