[Bruce Edwards]

Paul,

Sorry it took me a bit to get back to you on this. You did not say, or I missed it, what intake you are running. If you are matching the cam and intake even Edelbrock recommends a 750 or even a 800 cfm.
As I recall the lifters you have are metered to bleed down at low speed to smooth out the low end. What the lifter does is drop the lift at low speed so the car will have more vacuum at idle and low rpm. As the engine speeds up the lifters do nat have as much time to bleed down and the lift goes up.
With out seeing the car and only going by what you have told me I would say that you should see a bit of improvement with a larger carb.
I have not played with the Avenger carb as yet so I will leave that to someone that has.