It does have the 518 now but I already have an A-500 for it, just one more thing to get around to. Also if it drops in and out of OD too much I can just wire up control of those for me to handle. The tires on the truck are brand new 235-75-15s so they will be there for a while and are not very tall. The 318 in my cuda had a low gear 904 and similar height tires and was bareable on the low end, on the highway it still wanted another gear. I am 100 miles from cities in 3 different directions where I live now, tons of driving on mostly flat ground 75 MPH.