I gotta throw my 2cents in on the gear vendor!! Great suggestion!! You can't go wrong. You could actually run a 4:10 rear and have much more run out with the gear vendor but with much more pulling power at the start!!
I had a GV set up on my '99 F350 7.3 Diesel and five speed transmission! I got it second hand from a good friend that ran a sprint car, he could haul his crew and 30 foot trailer with car and all his tools. He took it to Banks and duel turbo'd it then off to GV and added the OD, Replaced the super crew seats with spring steal jack knife seat/bed and put a carpet kit in the back with a limo window! He ran the semi pro modified circuit for two years before getting out of it and returning to his full time job!!
The gear vendor made towing so much easier, I never used it in 1st, rarely in second, but third fourth and fifth and that truck ran good!!
It was one of those I wish I could have back!!