Are you stating that front brackets DO work on the rear? Or are you asking WILL they work on the rear? You might get any bumper brackets to bolt or weld on the rear frame section of a 36' Ford truck, but they would not be correct. If a 1936 Ford P\U even had a factory rear bumper, the original brackets were a one of a kind shape, front & rears completly different. 67= rear 68= front, these pics are from Mac's.