Hi, i have a 1999 7.4 mpi motor and wanna hook up a in dash fuel pressure gauge up to it. I looked around the fuel rail and only found the caped shrader valve in the front. anyone done this to know how to get this done? And if so, were do i buy the adapter to go on the shrader if thats were it gos

Some of those shraders are 1/8 pipe you could "T" off of that. If you need to adapt off of the shrader, buy a fuel pressure tester from a auto part store and use that adapter. The reality of it is fuel pressure is rarely an issue and you'd be better off keeping the tester in the glove box and spot check the motor if it's running goofy. One less place to leak fuel.

i'm not sure i agree with this for a couple of reasons. certainly on a carb motor where the fuel press is single digits and less critical , getting meaningful and accurate number is iffy on a dash but on an injected motor where you live and die with fuel pressure, having that on the dash is important. and i would make the suggestion that you isolate the sensor as opposed to a solid installation on the rail. by that , i mean, rather than screw the sensor directly into a threaded port on the motor, you use the appropriate adapters and actually attach it by means of a short piece injection rated fuel line and tie it off to rail or some other convenient location. this isolates the sensor from the vibration and heat of the motor and will give you more accurate readings and make the sensor last much much longer. on the race cars this method made the difference between throwing pressure sensors away all the time and having maybe an isolated failure once a season and it took all the noise out of the data.