I have built a few rods in my life and mixed new with old (1980s being the newest til now), but I have run into one I am at a loss on. I am building a 49 Plymouth with a 78 318 backed with a 5 speed from a 99 Ram 1500 and a 67 Mustang 8" rearend. The speedometer senser was on the rearend of the Ram 1500. Not in the trans. Where do I hook up a speedometer in this old and new mismash? Is there a way?