2002 Skidoo 700 mod sled build

I had the chance to buy a mint 2002 legend 700 with mechanical reverse, 121 track, electric start and all the other luxury items, got it pretty cheap and it has low kms. I had a chance to drive it in to my camp earlier this year and besides having the worst suspension and lowest handlebars I like the power of that 700, started in minus 30 with no issues, idled all day long, didnt miss a beat.

My buddy that owned it bought an Alpine 2 so sold me the legend cheap. So, now comes the part i like most, modding it. I am going to mod it in one day from top to bottom, take all my stuff off the polaris and swap it to the 700 and call it a day. I like the XLT mod but i drive to remote places and the triple is good but I am going to blow it up sometimes soon the way i drive - and in the worst place. And... the 700 will give me more hp to play with right away.

Here is what I will do:

159 track
8 tooth drivers
19t upper
keep reverse
ditch the e start
ditch the hood for a lexan hood
gripper skis from the xlt
risers and bars from the xlt
crank up the front suspension
install my rev xp suspension with rail extension for this season
buy timbersled rear this summer
crankshop pipes/head shave and reeds this summer (about 13hp??)
ditch the seat install my polaris seat
install tunnel extension from polaris

Questions:

1. will my hyvo gears and chain from the xlt fit the doo??? the chaincase looks the same! same splines???

2. would i need to put a clutch kit in???

3. will the 2 inch track fit under the tunnel with the 9T drivers?? (are they 9 tooth factory drivers?) I have 8T's to put on if i have to.

3. anything else i should do?

Pics coming soon.

i suspect you have to run race fuel with those heads?