Its a 400 BB in my truck. It runs 100 psi regardless of anything,(according to the gauge in the dash)

When I got the truck last week it ran like crap and I decided to tune it up. The plug wires were off 1 tower to the right(counterclockwise) it runs better,but still runs like crap,no power and stalls at stoplights. I timed it and its right about where it needs to be.