What kind do I need to buy? Electical right(or Mechanical). how do I connect it to the lt1? I wanted to buy the Autometer Phantom to match my tach

 

theres a few differences...
the electrical gauge uses an electric sender unit to send fuel pressure measure to the gauge... this basically means you can mount the gauge inside the car because there wont be any fuel lines past the firewall... i know that an autometer sport-comp electrical fuel pressure gauge is $190

mechanical fuel pressure gauges must be mounted outside of the vehical.. e.g. mounted in a cup on the hood.. this is significantly cheaper... probably under 100 for the gauge..

now you will need to find the bleeder valve behind the intake manifold. you will need to connect -4an line to this bleeder valve and connect the other end of the line to the gauge.

 

where can I get the line from I know where the bleeder valve is on the fuel rail--Schrader valve? I can use that one right

 

yes you can use that...also if you want the gauge in-car but keep it cheap with a mechanical, they sell a little dohickey called in isolator that you can hook up, that way its only water running into the cabin and not fuel. for ease of install and mind, id go with an electronic one. no chance of lines getting knicked and stuff.