How to test fuel pump? How to attach pressure gauge?

1973 Dart Swinger 318 V8 100% stock. Carter BBD 2 barrel carburetor. No power brakes. I started a thread on this on May 12 2022 in the "small block mopar engine" category TITLE: "Stock 1973 318 V8 starts but won't idle without foot on pedal.

I had the carburetor rebuilt and that helped. I don't have a lot of faith in the "professional" who did the rebuild. He did not do any other diagnosis. The car is driveable now but the idle is still rough. It smooths out at higher RPM. The idle is set at 800 rpm. It should be 700. I have timing light, tachometer, and vacuum gauge.