I think that is more smoke from his pipe. I would find it hard to believe running a rear backwards for 500 miles under essentially full power would work for more than 10 minutes. The engagement angle is optimised for one direction, and then there is the lubrication and drainage issues. I do not know if Hudson trucks were ever equipped with 4WD but a chunk from one may solve that. Now the dizzy, oil pump, water pump would still present issues.
The "mighty" Ford 10. Our Co. inherited one in a merger and my brother was driving when it decided to externally haemorage right in the middle of the road! Nasty oil drop to be cleaned up.