Hello,
Brand new member to this forum!! I've been lurking for quite some time and have gotten a lot of good advice here. I just recently ordered a set of Cal Speed LT headers, a Circle D 3200 converter and a Corvette servo for my 2008 Silverado.

I've read a lot about leaky transmission cooler lines on these trucks, and am thinking I will fix it while I'm putting all these parts on and before it becomes a problem. I already have an external trans cooler and I'm wanting to change the cooler lines to AN style fittings/hoses.

I've done a bit of research, and I cant seem to find what size the cooler line threads are coming out of the side of the trans. The only thing I could find said they were 1/4NPT which just doesn't seem right.

Any help would be greatly appreciated!!!

 

They are 1/4" NPSM, untapered, with an o-ring seal. (Threads look and measure nearly the same as 1/4" NPT but to not taper) There are adapters made intended for this purpose in -6AN and -8AN. The -6 plumbing is adequate.

 

Dang, I didn't even realize they were that small. I found the fittings and thanks for your help!!!