Timing by Vacuum Reading?

bob mCcarty said
RRR , that not too quick with todays crappy gas ?? I always thot it might be ok , say for higher octane , asking for a friend , ------------as they say !
may need to bring mine in quicker , all in at 3400 on 93 pump---??/

You never know till you try. It might be. But just do like I said and back off 2 degrees at a time until it stops rattling.