Pump and injectors are already replaced. The a/f shows some erratic readings consistant with wavering fuel pressure.
The fuel pressure gauge was ordered about 3 weeks ago (supposed to ship anyday now...of course). That will answer a lot of questions, but I'm wondering if either the pump (walbro 340) or the rails are holding it back.
Thought I'd see what kind of hp levels guys are running stock rails up to.
It's more a question of the total fuel system than just the rails. At some point past 600 HP, it's pointless to stay with a system that has the regulator in the tank. A return setup will have much more stable pressure and be far easier to tune. The stock rails, however, do have a pulse dampener built in, which is seldom added to aftermarket rails. They could be used with a return system, but most people going that route don't retain the stockers.