PATC overdrive kit

well strange thing... on the site it says they have one for the 518's, you get the box it says 700R on it. you call and they say they dont make one for the 518.

Now, you can make it all work easy peezy, you just need two pressure switches, the vacuum switch, a relay and wiring.

once you get it tuned with the vacuum switch and correct pressure switches it works great!