ok so i ordered an Adjustable fuel pressure regulator with a return port because im swapping from EFI to carb and still using the EFI fuel pump

This AFPR has an Inlet a return port and 2 outlets
I bought it because i was going to order a carb that needed both, but i went with a cheap one from a friend until i have the money that only has 1 port for fuel

SO if i have 2 ports on the regulator and only need one can i just cap one off? or will that mess with something in the regulator??

 

Cap it off. That's what I did and don't see any problems to it.

 

Yup, they are designed for that.

 

I used all three supply ports. Two for the carb. (one to each float bowl) then I put a fuel pressure gauge on the third port. You can cap them though.

 

Well, let's think about it. The FPR pressurises fuel and adjusts the fuel pressure down to the level you set.

Pressurised fuel is then delivered to the two outlets. Any excess fuel will be returned to the tank.

What's the difference between one port sending fuel to the carb and the other port smacking the fuel against a cap? If your FPR is working correctly, nothing.

So I think you're okay. Just make sure the cap is pressure tight.

How about throwing a pressure gauge on there?