i just got a new 600cfm edelbrock carb, and got a quick question about something i saw on jegs.
There is a kit for like 5 bucks that offers a bunch of step up springs

BLUF: what are the step up springs used for, are they worth getting, and will i catually need them?

ive heard of changing the metering rods but not the step up spring, thanks for the info, i know i ask a lot of questions, thanks for putting up with me

I have a Edelbrock 600 cfm too and got that kit with all of the different jets, metering rods and springs and went thru the manual and changed things to see what would make a difference...here it what it says about the step up springs...

The Step-Up function, which moves the Metering Rod to the Power Mode, is controlled by the Step-Up Spring. The base calibration has a spring which "stages" rich at 5" Hg.
If your vehicle has a mid-throttle driveability problem that is encountered as the throttle is gradually opened, but then goes away upon further opening, it may be possible to eliminate the lean spot by using a stronger Step-Up Spring. The available Step-Up Springs are listed in the following chart along with their respective "staging" point. It is best to select a new spring on the basis of vacuum readings, but in the absence of a gauge, try the strongest spring

(highest vacuum rating) to see if the problem goes away. If the drive problem is cured by the strong spring, try the next weakest spring as well. If the strong one does not help, then the calibration problem is related to the A/F metering stage of either the Cruise or Power Modes. Use the Calibration Reference Chart to help select another combination.

Spring Color Blue Yellow Orange Pink Plain
Staging Vacuum ("Hg) 3" 4" 5" 7" 8"


A complete set of these springs is available separately as Edelbrock part #1464.

was it worth it to get the whole kit?

Well the kit cost me about $53.00 from summit and it has all of the jets, metering rods, springs so you can fine tune to your liking...out of the box the edelbrock carbs probably run good enough you dont really need to change anything for it to run right...but i just cant leave stuff alone :P so i fiddled with it and ended up getting a little bit of an improvement in my gas mileage and feels like a bit more power too...so is it worth it??...you dont really need it i guess but its more of if you want it :P

Edelbrock 1405 tuning kit (http://store.summitracing.com/)

Ask yourself two questions:
Is engine running poorly? and
Do I know something about carb tuning?
If the answer to both questions is no I would forget about the springs.