Spark Plug Gap = .030
Point Dwell = 26--31,
Point Gap = .017,
Timing and Idle should be set to specifications on Engine Decal, but if it's missing, set timing at 6 Degrees Before Top Dead Center with vacuum advance disconnected and blocked and idle at 550 rpms. NOTE: If Auto. Trans, set idle at 500 rpm in Drive.

You might want to check out your vacuum advance and make sure it is operating as it should. Sounds like you might not be advancing as the rpms increase. Advance could be sticking or hanging up on condenser wire, etc.

Hope this helps a little..... Good Luck!