Looks like the carbs are jetted "Stock" which means your Idle holder should be 120. I have a 294 C.I. SBF with a cam that is not quite as healthy as yours. Here is what I ended up with...
Idle Jets 60F10
Idle Holder 110
Main Jet 140
E Tubes F7
Air Correctors 100
Make sure you set the floats at 5.5mm. Get the float gauge tool from Gene Berg. If you want to save some money, get some drill bits from McMaster Carr & start soldering & drilling your your jets until you find what works. Then buy the correct jets once you get it all figured out. Start with the Idle circuit & work your way through to the air correctors. Many of us here have done it with success. It can be frustrating, be patient & settle in for a fight!
One piece of advise I can give... Don't skip a size in jets. I had 135's (Main Jets) in the car & it stumbled. I put 145's in & it stumbled. I put 140's in & stumble disappeared. Webers are very sensitive.