The marauder seems to have a similar style to the ASW Zircon. Maybe you could just switch out the rear swing arm / sub frame. Maybe just weld some brackets on. Maybe just buy a 150 project buggy and build that up. My ASW Carbide 150 is 24" from outside bracket to outside bracket. I started a thread on this before when I came to the realization a lawn mower type engine had little torque.
http://www.buggymasters.com/forum/showthread.php?t=4152