Update from the road June 21, 2021. Our all new overland expedition truck is here! The Mercedes Unimog & overland expedition trailer have been sold. I have moved into the new overland rig & I am back on the road. Find out all the details here. 1994 Stewart & Stevenson M1079 van 6.6 Caterpillar turbo diesel engine Allison 7 speed automatic transmission Full time 4x4, CTIS, air ride cab, air brakes & more!