a friend of mine just purchased a Bush Bog 8' twin spindle, nice machine, every bit as heavy duty as my Rhino...the drive shaft is too long, so he's returning it to dealer, although i think he'll have to measure & cut...my question is how much allowance should he figure for the slip joint? around 1/2"? once mounted & in operation, how much does it actually travel? just so it doesn't bottom out, etc. thx!