It's going to have to depend on the trail the X is on. If by modded out you mean 6" of lift w/ M/T's, solid axles, etc. Then the 4x2 will do fine for the most part. Run into some slippery rocks or a muddy incline and I'd have to go w/ 4x4. This whole thread, if it gets big, will turn into a bunch of what if's.