That truck most likely has a 3.42 rear axle. If possible have it changed to a 3.73. Have an additional transmission cooler installed and have the oil lines installed so the new cooler is installed AFTER the radiator. Place the new cooler forward of the AC condenser. Everyone will want to install the oil lines for the cooler before the radiator but don't let them. You want the tarns cooled not heated by the radiator.
On mine I remove the transmission cooling completely from the radiator and run the trans at 160 degrees but it is not worth that now on a 96. The only reason they originally put the cooling in the radiator was for quick winter warm up.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles