1970s 1970 Fleetwood vibration

[jwwseville60]

On my 1970, the engine runs smooth. In neutral its smooth, but
when I put it in drive it vibrates the whole front end when stationary.
73000 miles on her.

Runs perfect at speed.
What could this be?
A bad torque converter?

Thanks!

["Cadillac Kid" Greg Surfas 15364]

First thing I would check would be the distributor vacuum advance.
Greg Surfas