My friend has a 88 maro with an lt1 from a 96 or so... basically its running like crap.. reason being is fuel pressure is way too high.. its running around 70 psi.. he's tried replacing the pressure regulator with another factory unit but still has 70 psi.. what else could it be?

 

A restriction in the return line? Does it stay at 70 psi during a WOT blast or drop some? What kind of fuel pump?

 

it stays, that was my guess too.. havnt tried anything yet though

 

I believe no one else has replied primarily because Lo-Tec nailed the cause. There's nothing else to say, other than we're waiting for you to find what the restriction is caused by.