I’m installing a trans cooler and I’m going to install a AN x tube adapter. I just need someone to verify the tubing size. I’ve seen someone mention 5/16” but then I’ve also read something about 3/8”. I also have read the trans fittings are 1/4”. Can someone please tell me what size I need to buy?

I’m not needing a 4L60E fitting. I need to know the factory tubing size for the hard cooler lines.

So I can buy a compression x AN fitting.

3/8 stainless compression fittings worked well on mine adapting it from hard line to hose. I used a tubing Union to go from the stock lines to the new tubing, ran up to the cooler with more stainless hard tubing and just a short section of braided hose to isolate the cooler from vibration. I also deleted the stock radiator cooler. Just straight from the trans, to big cooler up front, back to the trans. We don't need the pre-heat down where we are, and eliminates the failure point of the radiator cooler rupturing and killing a trans.

Yeah, I'm still hiding around here. Numbers still the same. I'm not playing with hot-rods much these days but I still have toys

I know what ya mean. We're expecting our third little one in October lol.

Dont be a stranger!