KidWgn
Certified Kid Hauler
What gears are in yours, how do you drive, and what stall do you have?Something else may be going on there. My trans temp with the stock cooler has never gone over 205, when not towing, in the same climate.
What is the engine coolant temp when your trans is 223? Is your fluid and filter fresh? Cooler fins clear? Do you have the oil cooler also? Electric fans working properly?
I can't imagine the differences in the front grill openings between a Tahoe and Yukon making that much of a difference
EDIT: I have had a Diablo tune installed since day one of having this rig. It may have the fan on/off temps come on a few degrees cooler than stock, which I'm sure effects trans temp
I have a 3200 circle d stall in a brand new transmission, with a new filter and Amsoil fluid, with 3.08 gears. The 308’s create a LOT of downshifting.