Ok, so i carbed a LT1 with a cam and some heads and whatnot, the usual, and i put a fuel pressure regulator on it, the mallory 4309 i think, the one everyone under the sun uses, now, is soon as i go over 3.5 psi it starts pulsating up to 4 or 5 and back down real fast and you cna hear a clunking at the pump, now, i ran it at 3 psi for about 10 mins and went for a ride and it was fine, what the hell is goin on, anyone...

 

what pump are you running?

 

stock 350 tpi pump, its steady now at 6....i donno...