Technical Speedo hookups (mixing new with old)?

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?

 

What squirrel suggests below!


Posted using Full box of Crayons on the Kitchen Walls App!

 

http://www.abbott-tach.com/cablex.htm

and

http://www.summitracing.com/parts/rpc-250-4165

but talk to Abbott first, and see if it will work

Or put a proper, older transmission without so damn many gears in it...

 

Since you are into it this far I think your only option is a GPS speedometer. Take a look at www.speedhut.com
They make a quality product. Classic instruments also has their Sky drive system. Good luck.

 

The GPS was the one that I didn't want to go to because of prices, but that seems to be the only true answer with this combo. I thank you for your input. Changing the trans. is out of the question. The hole running gear combo was based around the 5 speed. To change the trans. to fewer gears is just pouring more money in the tank. The GPS is the answer. Thanks again guys.