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
I have and still use the two piece dis. wrench. If it does not work for you, you are not using it correctly. I turn the Vac can away from the hold down bolt and snug down the bolt, but can still turn back the vac can where about it belongs. Start car and set timing. Now tighten the bolt the remainder way, like a quarter turn. DONE!!!!