Distributor vacuum advance hitting intake.......

All my life I used the "then popular" 2- piece KD tools with the connector piece in the middle. 1/2 on one end, 9/16 on the other. When I had the part time job at the NAS Miramar auto hobby shop, I used that on every car you can think of. Fords, Poncho's, Olds, Chev, and Mopar. And a few more.

kd tools 2 piece distributor wrench - Google Search