Not sure on the '04+ cars, but I thought the '97-03's sat around 45~ psi.
If you can, get a pump re-wire...again, with the returnless system the newer cars have, I haven't really looked into it.
Stock injectors I do know though are pretty lame on those cars, and run static pretty quick...I'd also recommend just picking up EBay stainless steel headers...I had pacesetter's for years...while good headers, they have larger primaries and they suck unless you hack up the downpipe and have literally everything welded shut.
I'd rather get the cheapo stainless EBay headers...and I had those as well after they were released...only thing those need is a modded downpipe to get rid of the gooseneck that hangs low...and a better flex pipe or delete the one they give you and just run a piece of straight pipe in there.
