/6 Timing has me stumped!

I have set distributor as advised! Won't run if turned 180° from current location. Only position it is happy in right now is 120 out. But thanks.

Then you need to find true TDC and check all of your marks. Timing gears and balancer. If they are all correct, remove the cap and see where the rotor is pointing. If it's not pointing to number 1 with the engine on true TDC, pull the distributor and point the rotor to number 1.