hello ...here is a question for you...what spring color are you using in secondaries? the 1 that came with the carb?.....or have you changed it?
maybe you have tried this, but buy a spring kit and try different color springs...each has a diff tension...sounds like you need a stronger spring.....
1) buy the Holley secondary spring kit
2) start with black spring(strongest-doesnt allow secondaries to open very quickly) then ...
3) Try other springs(color coded) ....till u find best 1 for your set up.....
this does work....
hope it works for you.......
