In a nutshell, if you get a similar year IH front axle with the steering linkages, no ... but you're going to want to get the 4x4 power steering box mount, too. I've found that it locates the steering box a little lower than the 2x. And, the mounts are different from '73 to '74/5. I've never played with manual steering so I can't answer that. The front springs on a 4x4 are shorter so you may want to consider that as well. If you can pull off the little IH 4x4 shock "towers" that would be a plus. Not hard to make if you can't - a very basic design.
There are a variety ways of doing it. I've done both using an IH Dana 44 and also a Chevy. The IH obviously easier but the Chevy easier to get parts for in the long run, especially rotors. And it basically bolts right in. Mine had the bigger tube so I had get bigger u-bolts. The red truck below has a '77 Chevy 8-lug Dana 44 axle using '71 IH 3/4 ton front springs, '73 steering box mount, a reemed '73 pitman arm (longer than the '74/5), a '74 draglink (thicker than the '73) and steering arm. Of course, aside from the linkages there are the brake lines, shocks, and proportioning valves for disc brakes.
The yellow truck is a 1110 with '70 3/4 ton IH stuff I got from Pick n Pull. Both started life as 2-wheel drives.
