RW, trucks looking awesome!! I'm amazed at the short turning radius it has and I wish mine would turn like that. Boston gear make a bunch of universal joinst that would work in your truck. I've used them in my 3/4 scale SD-40 for over 20 years and never had a bit of trouble. Run up to page 100 and they start from there.
Rob
http://www.bostongear.com/pdf/open/5...en_gearing.pdf