First and foremost,
WELCOME TO THE SITE!!! I'm the local pain in the arse.
Gator tranny - I must say, that's a new one. Seen/heard many ideas, but this one's new. I like it - it may have merrit.
Okay, let's get down to business.
Do you, by chance, know what gear ratios the Gator tranny is? Pilots are roughly 10.something (I want to say 10.8?):1 forward, somewhere near 11.something:1 in reverse and, obviously neutral's whatever to 0.
Stock engine needs the stock gearing in forward. Once you start adding HP, then you can run lower ratios - albiet you can't get lower ratios for the Pilot tranny. If you start messing w/the four strokes, they'll allow taller ratios (Gixxer would probably be happy in the 6:1 or less range)
So, if your Gator tranny's a lower ratio, you're going to want more HP.
I'm out in left field on the idea of a diff in a Pilot.. Hmmm.... Dunno!!! :? Could be interesting.
I'm so used to my off road vehicles having a live axle that the diff idea's foreign to me. I steer with the rear end and brakes/throttle as much as I use the steering wheel, so a diff would take me a while to adjust to.
That said, I know of a couple guys that run single seat cars w/a diff and love them - so I would imagine that a diff would/could add a new dimension to the Pilot.
The fact that you could lock out the diff would be a plus. May only want to unlock it during tight riding, such as in the woods on narrow trails.
What about the output shafts of the Gator??? The Pilot has about 2" (pardon, about 52mm) of plunge on the inner CV joints. If the Gator has the ability for a plunging CV (do the Pilot inner CVs happen to plug into a Gator??? - probably not - they don't go into anything) you may have something that could be pursued.
I would venture a guess that the Gator tranny would be strong enough. The Gator's a tank compared to a Pilot - and it's design is load bearing and such, so it's probably strong enough.
Does the Gator use a CVT (belt and clutches) drive train? Do you know the input shaft diameter?
Speaking of turn brakes (I think you called them fiddle brakes?) - not fun when you're racing in a live axle car, right on the guy with fiddle brakes back bumper, going into a corner and he's suddenly completely sideways in front of you and you're heading for his side panel. YIKES!!! I learned to change my line and avoid him - was fun, though!
Posting pix is actually quite easy.
In the upper left corner, there's a window that says "Message body" and "Add an Attachment" - just follow the instructions.
If you need help, you can send me the pic and I'll get it up for you.
Once again, welcome to the site.
Oh sure - beat me to it Nuke Em - here I was, one handed typing and you come along and take the subject...