1988 Suzuki LT4wd New quad, few questions.

[white00s10]

Just picked up a 1988 Suzuki LT4wd for $500.00 off craigslist, I just got done restoring a 1989 Yamaha Big Bear 350, and i saw this quad had the 6 select-able ranges and I fell in love with it.

Im fixing the brakes now, moving onto carb soon, Im a machinist and have a good mechanical inclination, but im totally new to ATVs (took me a full week to figure out my lean condition on the big bear wasnt a clogged jet, it was just missing the rest of the intake tube).

few questions

1.) i put the quad up on stands and started to pull the brakes apart, came in the garage today to see half my front diff oil on the ground (pinion seal) id like to replace it, and im just wondering if its bearing style pinion, or crush sleeve, and how hard it would be to replace the seal (and bearings if they're shot). Is it built with looser tolerances (backlash and pinion depth etc) or is it like a vehicle diff where you go to get it dead on or your burn up the gears?

2.) I was told fenders from a LT4wd, lt250, king quad etc, will fit (from up too 2001) is this true? My plastics are FUBARd, and i wouldn't mind going to newer style wider fenders (providing the attachment points are mostly the same)

3.) I LOVE the front diff lock feature. I hate that itll only engage in super low. I do like my mud pits and keeping wheelspin up while going in a straight line is ideal for me. i have heard mutterings on the internet that there's ways to modify the shifter assembly so itll engage in ranges other than super low. Again, is this true and or is there a writeup about it?

Im sure there will be more questions, but for now this is all i can think of, thanks again!