I wasn't sure if this belonged here or in conversions, so i picked here.
I have a 99 Firebird that i'm trying to finish up swapping a 98 LS1 into.
When i prime the fuel system, I'm reading 70psi on my fuel pressure gauge. At idle i'm seeing 90 psi...
I'm at my wit's end and am convinced it's something stupid and easy that i'm just overlooking. The engine is completely stock minus a set of TSP Longtubes and an LS6 PCV conversion. The in-tank fuel pickup was replaced with one off of an 00 SS so that i'd have the fuel pressure regulator. I'm still using the 99 v6 fuel lines, but i believe lines should be the same size.
I've considered swapping to a vette LS1 fuel rail to utilize my return line again and get the FPR up on the fuel rail again. I still have my v6 pump assembly with a racetronix pump that i can swap back in.
Any ideas at all? I'm stumped and really want to drive my car again. It's been two years since the last time.
Waaay too much fuel pressure after engine swap 
