i just built up a 83 about a week ago i got it running, it has the motor from my old 88 which i recently sold. i have a weiand stealth intake, holley 750 3310 on my 331. it pulls till about 5500 in second then falls on it's face, the plunger doesnt move when i make a pass, i have a ziptie arond it enough to where it would move it if they opened and it has never moved. should i get a lighter spring? i got the carb used and rebuilt it.

 

Make sure the linkage is allowing the throttle to open all the way, make sure the secondaries aren't sticking, preventing them from opening. If you hold the primaries open to clear the linkage and let the secondaries open, and open/close it with your hand(engine off obviously) you should hear some air hissing through the carb as the diaphragm pumps it through the vacuum channels. Verify nothing is preventing it from opening first, and that there's no vacuum leak in the secondary vacuum actuator circuit, then try a lighter spring.