Installed a tranny cooler in my truck this evening and I thought it might be useful to post some pics for you guys.
I installed a Hayden 679 plate and fin cooler in my 2013 Chevy 1500 W/T with the 4.3 V6. I tow a 4000lb or so camper, so I'm right on my tow limit, so I wanted to keep the tranny extra frosty.
Cooler - https://www.amazon.com/gp/product/B000C3BBKS/
You will need this adapter to connect to the stock cooler built into the radiator. https://www.amazon.com/gp/product/B000EPRCAC/
Pop the hood
Remove cowling over radiator. Its just plastic pop rivets, you use a flat head screwdriver.
Remove 4 10mm bolts and then pop the grill off.
I attached the cooler to the A/C condenser. I was going to make a bracket and bolt it in place, but I couldn't find anywhere I really l liked it that it was secure and got good airflow. I've had one attached to the radiator on my honda civic for about 100k miles now with zero issues, so we'll just go that route.
Super duper easy install. You pop the clip lose holding the tranny line hose in the top of the radiator and pull it out. Connect one of your hoses to your cooler to that. To the other, attach that adapter you bought and pop it into the radiator and put the clip back in place.
This video shows it in more detail if you have any questions.
Pop your grill and the cowling back on, add 1/2 a quart of fluid to make up for the extra capacity you just installed, and your done.
Took me about an hour start to finish.