After doing all the research and homework on here, I decided to stop and pick up the 37337 this weekend to install since I was doing the pads and everything anyhow.
Problem- Napa specs show the 37337 as having line thread size of M10x1 where as the stock replacement called for 9026 which has line thread size of 3/8x24.

I did not find anything upon searching all the threads that any adapters or new fittings were required to fit the current lines to the new 37337. What have you all found?

 

Most likely the Napa specs are wrong. I've installed the 37337 cylinder over a dozen trucks, nothing extra besides brake fluid is needed. It's a direct bolt up.

 

Thanks I will be sure to triple check though just in case so I dont end up stripping something. Just my luck would be that I got the only 2 in the world with different threads. Full bore ahead now!!!!!!!!!!!!!!!

 

I just did mine the other day and they didnt seem to want to thread in very well, so I just threw some thread tape on and away I went.

 

You do realize that the treads do not do the sealing in any way shape or form? The flare on the line seals it...

 

Hey if it makes him feel better about it then it's worth it.

 

So could it be that they are actually different threads but so close that some dont realize this? Hmm has me wondering.