Hello gentleman. This is my first post and I could use some help/advice. My truck has a 400 with a three speed (plus granny) transmission. The seal went between the transfer case and the tranny so the tranny fluid runs into the transfer case. Do I replace the seal or bite the bullet and switch to an auto trans? If I go auto: 1) What tranny will bolt up to a 1979 400? 2) What should I switch the ring and pinion to so I can get more speed out of this girl? (currently 50 mph and she is screaming) 3) Do I need a donor truck or can I work it out with the brackets, etc. needed for the swap? Im not sure of the gears in the truck. Would the auto tranny be enough to gain some additional speed? Thanks for the help.