Large RPM and Vacuum drop when shifting from park to gear

Hello everyone!

So, it looks like timing is the culprit. Disconnected the vacuum advance line from the manifold and plugged it. The engine ran like crap in park. So, I advanced intial timing by turning the distributor. Idle quality began to improve but....... I cant advance it any further because my advance canister is hitting my intake manifold. How could I solve this?