total timing is set at what rpm

Longgone said
Literally total timing would mean the sum of initial timing, mechanical advance, and vacuum advance, but most everybody refers to total timing as initial and mechanical only as the vacuum is removed from the equation (plugged) when setting the total timing. An example of 34* total timing would be 17* initial and another 17* mechanical. Vacuum advance could add another 17* for a total of 51*. Total timing on many vehicles with vacuum advance in the circuit can easily run in the 50`s depending on the needs of the engine. Most everybody running their cars on the strip will plug the vacuum advance since the only throttle position the car sees is wide open. I agree with Stroker Scamp on the use of the vacuum advance around town where most of your driving is below 3000 rpm. The car will have smoother throttle response and get slightly better gas mileage. Detonation can be a problem with the gas that`s available today but with moderate compression and several high gear/low rpm acceleration tests, you should be able to find a timing setting that you and the car can live with. As already mentioned both the mechanical and vacuum advances are adjustable so you can fine tune where and how much advance you add to the initial timing.

LOL. You're preachin to the CHOIR and don't even know it. Let me break it down for you. "I" don't worry about initial timing. It's irrelevent. All you need is enough for the engine to run so you can set the rest. I remove the vacuum hose from the can and run an extension to a vacuum gauge taped to the windshield. I note my vacuum reading in high gear at 2000 RPM while just cruising. It is at this point that the timing should be all in.....at least for "me". Then, I go back to the driveway, disconnect the hose and reconnect to the vacuum can and take a timing reading at whatever reading I got on the vacuum gauge. It will of course be at a higher rpm, since we are now static in the driveway and not under load. This is why you don't use a tach to set timing. I let the mechanical advance in the distributor alone. I simply limit the vacuum can to whatever I want the total timing to be at at whatever given vacuum reading I got on the test drive. This is actually the most accurate way. While it's true you can play around with the mechanical advance some, I have found through the years, very little performance advantage in doing so on a street car. Of course, if using only a mechanical advance distributor, you must address adjustment, since that is your only means of advance. I have only on one or two occasions in better than thirty years found it necessary to adjust mechanical advance in a distributor using a vacuum can. I've read all the books. I've spent time at the tracks. I've set it to the inth degree as described above, but this method has worked best for me. It will on any street car, too. It's a good shortcut that will get you so close if not right on top of the technical guy's timing, it ain't funny.