upgrade transmission cooler

Technically a stacked plate type is best, but tube & fin coolers will work just fine too. The former is more expensive. Both are fairly easy to mount (depending on available space in front of the radiator/condenser) if you have decent mechanical skills.

What kind of temps are you seeing? Do you have the additional cooler up front? If you look through the grill you should be able to see it sitting in front of the radiator. If not, you can buy the additional oem one complete with actual trans lines and cooler for less than $100. You can have the dealer do the install, probably for right around $200.

You can do the install yourself, but let me tell you, it isn't for the faint of heart. Disconnecting and reconnecting a trans line a blind location, and thats after you have used your rubix cube knowledge to route the hard line back through everything. If your not handy or lack patience, the money to have it installed is well spent.

If you already have one there though and just want something bigger, it should just mean disconnecting the old, mounting the new and hooking up a couple of short hoses to the existing fittings.

The Tru-Cool coolers seem to be the best. I almost did a cooler upgrade on a NBS 1500 Silverado but sold the truck for my 2500. Anyway, here is a link to an install that gives you the size perspective on the Tru-Cool 40k linky