[decooney]

aside from the sticking throttle situation... (Not Good)...

do you have a fuel pressure regulator in the system somewhere?

did you "replace" the needles when you went through the carb(s)?

Also... I'm wondering if the needles (rubber tips) are slightly compressed or have become hardened now (sometimes not visual to the naked eye) and if you are blowing the needles off of the seat right at 6lbs. I take the needles "out" of the bowls, blow them out with compressed air to be sure there is not some mild buildup or junk stuck in them. I had this problem once on a previous car from a crappy, generic/silver Kragen type inline replacement fuel filters where the glue from the NEW filter became dislodged and got stuck in my needles a few times til I figured out where it was coming from. Never used those generic type filters again after that. Good Luck.