Idle Rpm High in Park, Low in Drive

Dana67Dart said
It is normal for a carborator car to drop rpm when in gear.

A little. Like 50 rpm, not 150 or 250 rpm.
Some older, pre-smog trucks will just shift into gear with a manual transmission and need no throttle.

fishmens67 said
First thing you need to do is find TDC and mark the damper. initial timing is very important when tuning the idle circuit.

^^^This^^^^
Mark the TDC and then use a dialback or timing tape.
Or I suppose it can be scribed on with a bit moer dexterity and patience than I have.