So I got an AEM fuel rail to setup my car for E85. I'm trying to plug the port for the stock fuel pressure regulator but the plugs they supply only fit the 1/8 NPT port on the left. I called AEM and they were no help. Does anyone know if this is right?

Heres a picture, hole on the right:

 

so your saying its tapped 1/8th NPT and you need a plug ?

 

Most likely M8 x 1.25

Those are the bolt holes that hold the stock FPR down, you need a block off plate and two bolts to block it off.

 

Just ordered a 1/16th npt plug which I think is what it is. We'll see.

 

My AEM rail came with 3 plugs... 2x 1/8th and 1x 1/16th.

 

ordered..? thyre quite common..

I would buy that off you and direct you to a rail used for aftermarket FPR on the cheap

 

on my aem rail i used 2 1/8npt plugs.

 

JEG's is cheap, and stupid fast shipping. I ordered last night at 10pm and its already at my door at home. Probably easier then running to Lowes in rush hour after work lol