If you'd read the 1st link I gave you!!!:Posts #5 & #6
http://www.buggymasters.com/forum/showthread.php?t=1602
I showed a way to convert the shaft to chain. I'd have gone for the 250 because it's and semi-auto. I've spent a lot of time trying to see if using the shaft would work on a buggy. I have the 250es differential but making axles & drive shaft longer would be very expensive. I do custom stuff but I try to leave the expensive factory stuff alone in-case I need to replace it. So taking the drive shaft yolk (very common/cheap part) and converting it to chain only involving that one part and easy enough to make again leaving the buggy axle stock & availabilty to change axle sprockets for correct gearing.IMO The 4-wheeler rear ends are too narrow to use and be safe when driving hard. Just from my little amount of experience & testing you really need 44" hub to hub for a stable 2-seater.