Just wanted to turn all you Gm TBI owners onto this. Have trouble checking your fuel pressure without a shraeder valve? This adapter will fit inline with your current fuel line and you can leave it there. Any Fuel pressure tester will fit it check it out. Heres the link http://marine-performance-parts.com/...843505774.aspx

 

sweet, i have made an adapter that fits a quick disconnect fuel filter but it only works on cars with tbi

 

Yeah but this one can stay on there If you replace the fuel filter you have to take it back off. It is kind of pricey though!