[JL8Jeff]

You kind of made my point, the vrfpr gives a full 18 lbs of fuel pressure at full throttle(or lowest vacuum) and the stock fpr is only around 13 lbs and the other adjustble fpr's are around 15 lbs. So the vrfpr could be supplying more fuel than the others and give you a better idle to help pass emissions. As for the mods Tim said he already did to it, have you put a fuel pressure gauge on it to see what it's really getting at the injectors? I never installed it on my truck so I'm not sure what pressure I was getting. And I believe the 90-91 454 trucks had the 90 lb injectors so there's nowhere to upgrade to. Just a thought on getting more fuel into the engine.