Dizzy help

I have 72 Challenger 340 4spd with original std electronic distributor . It has FBO ecm box & coil. The engine has been rebuilt w hughes 220/224 hyd flat tappet and 9.5 cr. I broke in cam and found sweet spot for idle n timing. Idle 900 rpm and 16* btdc, 16 in-hg. I haven't got on road for full advance but want 34* limit. This will be cruiser only. I got a FBO advance limit plate to install, but have question now that dist is disassembled. Does limit plate go below slotted original? Also the weights had only one spring, a yellow. Does it need another and what color? Thanks for help.