First time Holley tuning help

What is the Proper way to adjust holleys and in what order? I have a 4160 converted to 4150 with vac secondaries. I am having an issue getting the off the line stumble out of her. Currently running 66 jets in primary and 70s in secondaries. Have played with the accelerator pump cams and have not found one that will take the stumble out. Engine is a 360 stock with a bigger cam and 2500 stall.

First of all I'm saying that she is rich because it doesn't seem to back fire and stutter but more of a lazy throttle.

Next my idle circuit and primaries look good for jetting but haven't been able to make enough passes to get a good reading on the secondary side.

Should the secondary jetting sizes be adjusted before pump cams and vac springs?

Tried pump cams all the way from the leanest pink to the rich blue but they all seem to have about the same effect just she takes off a little faster or slower.

When do you decide to play with vac secondary springs? Should I be playing with these the same time I change the pump cam to try to get the secondaries opening sooner if it's lean or later if it's rich?

Any more description on what I'm actually looking for when doing a launch to see if it's rich or lean. If it's lean will I be able to to hear it backfire at 3k rpm and open headers?

PS this is my first Holley