360 timing, help

It probably has the super light advance springs and no limiting of the slot. Put in at least one medium spring to hold the weight at idle and use a welder or solder to shorten the advance slots on the outside. You will probably want to disassemble the top of the distributor for this which includes the little snap ring under the rotor which can be gotten with needle nose pliers. Solder is easier to work with and holds up despite the softness of the material. Old fuel may also be an issue especially with iron heads.