The only problem i can forsee is the gap created between the inner and outer fenders.
The way I modified my fenders - I used a string and Majik Marker. I taped one end of the string in the center of the locking hub, and wrapped the other end around the marker at the prescribed cut-point. I then simply drew a radius mark from the bottom of the fender around the radius line till it exited the edge of the fender higher up. I then used a jig saw with a long, fine-cutting metal blade and cut the line, cutting both the inner fender and the outer fender at the same time. I then sanded all edges smooth and sprayed all raw metal with Metal-Prep, which is a phosphorus acid product which stops rust instantly. After this dried I sprayed red oxide primer on all surfaces. Then I got some fast-curing body seam filler from the body-shop supply house and filled in the space between the inner and outer fenders. This stuff cannot be sanded after cured so you have to smooth it out when it is installed. I filled the void at least 2 inches deep to provide a strong, long-lasting seal. After the seam filler cured, I simply painted the exterior green, and later I taped off the green and shot black onto the inner fender surface. It looks almost factory-done.
Hope this helps.
Thanks for the compliment. My truck indeed turns heads, and it is especially fun to watch the teenagers with baby trucks pointing at me when I come through town.
I bought my axles. Get dually axles. Stock H1's will look great on them. 
