Found some good info on the trucool cooler installs, figure I should sign up as actual technical info on the tahoe forums is almost nonexistent.

Looking to build about a 450 to 500 wheel daily driver and weekend tow machine. Currently have a 7x14 enclosed trailer for two track bikes, looking for more power and to keep the trans cooler on the long haul upstate NY and down to NC from central PA.

 

Welcome! Pretty color on that big girl!
Best bet for OEM parts and reliability for years is an LSA swap, or another form of PD blower

I dont know a whole lot about the 6L80, but you may look up the thermostat. I read a thread where the guy spent $4-500 on fittings and a cooler and it looked great, still ran 190°F and it was because the trans had a t stat.