I bought some MAC LT headers for my 2000 V6 and they have flare tube fittings on the front tubes of the headers. I have gone to True Hardware, Colburn's, Lowe's, Autozone, O'reilly's, Advance Auto Parts, and Napa. None of them have a flare cap that fits on the tube.

I had changed my passenger side header 5-6 years ago because it cracked. The one I got from Autozone came with the same flare tube for no reason but came with a cap, so I capped one header off with it. Now I'm screwed because I spent all this money on some headers that I can't even use.

Can anyone tell me what should I use to cap this off? What is the size? They've got to make a cap somewhere.

 

Go to lowes or a similar store. You need a cap with pipe threads.

 

It has flare threads on those pieces. On top of that I went to Lowe's and they had nothing. I don't even know the size of it. A 5/8 is too big and a 1/2 is too small.

 

It's pipe thread. Which is different from SAE and metric course/fine threads.