Snowmobile gearing help please

[jayjay283]

I have an artattack snowmobile, using my calipers its geared 13 Pinion 68 spur in 32p..( belt driven) .. it has no diff off course so I dont know what the end result will be... The drive pully (i suppose it called) that runs the track, is a 56t spur size. Anyone have experience with this. I have a 1515 1y or 1515 1.5d to run it with but is this way too slow ? I need a 5mm shaft for the nitro pinion thing to fit on and all my high kv motors (3000 kv+ are 1/8th) will it do 40 with a 1515 1.5d or should I buy say a 6xl ?