Late 90s+ teh Mags got a 1-piece damper/crank pulley, so you'll need to swap to an earlier 5.9 damper if you want to swap to V-belts. Timing cover and water pump and pulleys must be swapped as a system, don't mix-match parts.

There are a lot of subtle tricks on swapping Mags, and 5.9s are a little trickier than 5.2s. nothing that can't be overcome, you just need to know what parts to buy.

Look at Dippy.org, I've posted a bunch of Mag swap details over there (and here too, but not as much).