my truck did not come with a tranny cooler from the factory can i put one on it if i can how and which one should i buy

 

The factory tranny cooler is part of the radiator, unless you had the towing package which adds another small cooler.

Yes you can add a cooler, if you are in a cold climate area its best to add it inline with the radiation cooler. Lines are on the passenger side. "Long" brand coolers come with the fittings you need. With a stall I would get as big of a cooler as you can. Something in the neighborhood of 24,000 will be enough if you don't tow, but bigger would be much better.