do i need a adaparter for fuel pressure or water temp gauge i got a 2 5/8 autometer i know i might need one for the water temp gauge. but the fuel pressure reg is going on the fuel rail what lines do i need and how long. its an 86 and im going with the cowl gauge pod.
You do need one for both. The stock sending unit hole for a water temp gauge is 3/8" NPT, IIRC (get confirmation on that).
For the fuel pressure, see Jrichker's post about how he did his. He lists part numbers and specs. I've changed my stuff around enough that I can't remember what I used (In my piddling, I have used two AM 3200 series adapters, but I cant remember which was for what).
Many AM gauges have a 4 AN male thread on the back of the gauge. There's a slick 90* fitting that swivels for 15 bucks (for a cleaner install if you can see behind the gauge), and then you have your 4AN line and one or two of those AM adapters to get the 4 AN female line onto the Schrader valve's orifice. Again, JR's post will make a lot more sense than mine did.