Firstly - Big thanks to Marcos for helping me sort out the required size.
ANd for suggesting that you can indeed fit the 110 in.
The only reason why i didn't, is that i tried the 108 and it JUST just in without poking out the bottom of the chassis. I might get the dremel out and have a go at the motor mount because it really shoudl slide back a little farther.
So the cyclone isn't designed for the low low gearing for a 4.5 eh??
Better hope a 3.5 doens't pop out anytime soon..