Ross you may already know this process, but in case it is unclear or we are informing others, here goes. One adjustment at a time. Vacuum advance setting: Check your specs from the FSM. It is in the electrical section right before the schematics. (You probably already know this). I used a small hand pump vacuum actuator. First step, make sure that at idle you have less than 8 or so inches of vacuum going to the canister. If you have more than 8 your butterflies may not be seated (maybe due to too high of idle setting not allowing the butterflies to close all the way.) causing vacuum advance to open early. If ok, plug port from carburetor and hook vacuum hand pump to vacuum advance canister port. Hook up timing light and start engine. Start adding vacuum with your hand pump, watching your timing mark, when it starts to move record that spec and compare to the FSM spec. If it is opening sooner than spec you may get detonation on acceleration. If it opens later than spec you may feel a hesitation on acceleration. As said up above. Clockwise opens it earlier, counter clockwise opens it later. Mine used a 3/32” Allen wrench. Mine was opening at about 14” which was advancing later than I liked, causing a hesitation (I am running a 2bbl so may differ from your 4 bbl specs.). I dialed it back to around 10” per spec. Do a half turn at a time. This really helped my hesitation issues when stepping on the throttle, but not opening to early to cause detonation. Happy tuning.