There are options, but it's pretty much find a box and see how you can make it work.
I used an IH Scout II gear box on my 2 ton, but it won't work with the P-30 steering linkage, although it will work with 3500HD axle (I-beam) linkage.
The truck I'm working on now I will attempt to use a box off of an Isuzu cab over truck, should work with P-30 axle and mount more nearly in the original location, although inner fender trimming will be necessary.
Grigg
