Any PP spring will work with 18" vacuum at idle speed. They can be used for fine tuning even though any of them would be down at idle and cruising. They basically control the exact point where the PP raises the metering rods when engine load and vacuum drop off (heavy/full throttle). I'd start out with our light blue spring for what you are doing.......Cliff
thx Cliff, this is exactly what i am using right now in my other carb and i was goin to use in this one, blue spring. Well i actually started the car this weekend but it didn't want to idle at all. I changed jets and rods,in the end i have found that divider plate in secondarys hits discharge tubes. I hope when i fix it cover will be able to seat flush and seal idle circuit. There is almost 2 mm of free space between main body and cover at the divider. Maybe next weekend i will be able to check if it fixes the idle problem. Thanks,
