408 6 pack carb jetting

Id start with stock netting in the center carb, get all 6 bbl.’s to idle the engine correctly, tune the primary first, secondary second, springs last starting with the OE springs.

If spring changes cause confusion and fits, try drilling out the air bleed passage and install Holley air bleed screws to Taylor the timing and rate over the springs.

Check this out; TUNING A SIX PACK