personally here is the low down/forget the secondary spring for now you have to pull enough vacuum to open them and i believe the opening point is somewhere over 2000 rpm /if you nail it and the car takes off then bogs you are not feeding it enough gas go up on the jets/ your problem bogging then grabbing hold means you have too much initial fuel that carb probably has a # 72 or #70 main jet in it,what ever it has stock go down a couple of sizes reset the carb with a vacuum gage and drive it. if it quits bogging make a wide open throttle run and shut the car off before lifting off the throttle then pull a plug and read it / tan= correct size jet/black= too large jet/and if it is white = not enough the reason for shutting the car off is if you decelerate under driving conditions it will clean the plugs then you don't get a true color reading/ now once you do all this i like to change my shooters to the ones that have tubes in them they get the fuel right over the venturi i have had great success with # 31 but i was also running a #3310 750 vac secondary on a larger engine