3/4 ton 4x4 front axle width questions

[chevytruckguy70]

When it comes to 69 and 70 trucks, I've been a 2wd guy through 5 trucks. Now I've jumped into a new project that's a retired 1970 3/4 ton 4x4 fire truck.

The fire dept swapped out the front axle for a later model dana 44 with disc brakes and added 5 extra leaf springs in hopes of controlling the 300 gallons of water loaded in the bed. I have the original drum brake axle, it came with the truck when I bought it.

Now my question. The disc brake axle is 1 1/2 inch wider per side than the drum brake axle. This causes the front tire to stick out of the front fenders and, now that I've lowered the truck back to factory height, also causes the tires to rub the fenders when turning. Is it normal for the disc brake axle to be wider than the drum?

I measured the drum brake from ball joint to ball joint and get 54". Measuring the same locations on the disc brake axle I get 54 1/2". Measuring from wms to wms on the drum axle I get 69". The disc brake axle measures 72". This tells me the extra length is located on the spindle assemblies. Can this be swapped out with other disc brake spindles to be corrected or do I have to convert back to drum brakes to get my wheels back in the fenders where they belong?

BTW........ This truck has 15,054 original miles on it. You've got to love fire departments!