Going with a Transmission Temp Gauge is a Item you want to have when Towing, One route you could go and that is swapping out your Dash Cluster's with one from an Escalade or a Denail Dash Cluster, as they have the Transmission Temp Gauge already in the Dash Cluster.......and all of the 2000" and up Tahoe and Suburban's are All Ready Pre-wired from the Factory for the Trans. Temp Gauge.
Originally Posted by BillM
The extra capacity in the pan only helps for short term loads, like drag racing, snow plowing, and perhaps hard in town driving. They do nothing for extended load situations like towing heavy loads up hills for example.
Dex VI or Mobil 1 ATF will help slightly with heat buildup, but more importantly the synthetic fluids do not break down as quickly in the heat.