Need help with fittings
 

I have a 04 sierra. I'm replacing the trans. The radiator and the trans cooler. I want to change to an fitting. I like the looks and durability. But I can't figure out the fitting sizes. I've searched and purchased a few fittings that where used by others. I'm using 6 an line. I have a cold case radiator. They say the fittings are 3/8 inverted flares. But they didn't tell me the oil cooler size. I have 5/8-18 inverted. 3/8 npt. 1/2-20. None fit the radiator. And I haven't tried the tru cool cooler yet. Has anyone tried this.

Some good info here.

https://www.performancetrucks.net/fo...thread-470284/

Ive read through that and the fittings dont fit. But after doing some more research Ive found that maybe the 6an to 5/8 inverted flare fittings I bought are machined slightly off. So Ive ordered some more and lets see how those will work.

So I got the tranny lines and an adapters. Now Can someone help with the oil cooler side. The factory fittings are positive seal oring. M20x1.5. But I cant find that size with orings. Can anyone help with this