TODAY is a Great Day to visit our Store and order the parts you need for your truck!
14" behind the cab. Pick a spot that makes it easy to do a fish plate when you're putting it together.5" or 6" off the back. It doesn't really matter.My writeup: http://www.gwellwood.com/project-cars/the-crusty-chevy/shortboxing-the-frame/
This is on our main page under tech: http://www.73-87chevytrucks.com/lwb_to_swb.htm