What I said in post #3 is going to apply, particularly ign timing.
You get the idle timing dialled in first before touching the carb [ centri timing curve & WOT timing comes later.]
Idle timing is realllllllly easy. Set initial to about 12* BTDC, not critical. Disconnect & plug VA. Adjust carb for best idle.
Warm up engine, in gear, engine running/idling, turn dist slowly to advance timing. Idle rpm will increase; keep advancing dist until you get the highest rpm; toggle dist to make sure you have highest rpm. Idle WILL also be smoother. Now check the timing. If it is 45* [ more likely in the 30s ] , then that is what the engine wants for best idle/tip in response/cool running/avoidance of a flat spot. The easiest way to do this is using vac adv connected to manifold vacuum. A dist with an adj vac adv is reqd for this. Most adj VA units have about 30* of travel. So any combination of init + VA can be used to provide the # you got in the test. The reason the rpm increased in the test is because the engine was making more hp from the extra timing.
I suggest you do the above testing & report back with the #s.