[Excaliber]

I'm running right at 23-24 base, another 14 or so mechanical advance all in by 2600-2800 rpm or so and finally another 12 degrees of vacuum advance for a total of around 50-52.

23-24 might sound pretty high for a base setpoint but depending on your cam profile and fuel setup it's completely reasonable for a LOT of high performance engines. I'm convinced most folks don't run ENOUGH base timing and end up with "stumbling" on accelleration, or "bogging" and then spend days and dollars chasing the carb. Which often is not the problem!

Some disclaimers are in order for my setup:
1. I'm running a special after market mechanical advance limiting bushing on my MSD that is NOT available through MSD. It's a CNC'd special bushing that cost $40!! Ouch, but it's the only way to get a BIG base AND limit the TOTAL mechanical timing with a "ready to run" style MSD distributor. You don't want more than 36 to 38 total mechanical timing.

2. At light load cruise rpm a properly tuned engine can benefit from as much as 50 degrees total timing. The only way to get there is a vacuum advance. As this is somewhat controversial (running that much timing) there is virtually NO professional engine builder that would recommend it. To risky, they gotta warranty the engine or preserve their reputation. They don't trust you. They are NOT going to stick their necks out, so don't use a vacuum advance unless you know what your doing.
3. I built my engine with a compression ratio and a piston deck height, custom pistons, to specifically induce "quench" in the combustion chamber. I'm also running forged pistons. I did this so I COULD run vacuum advance, it was all thought out, including cam profile and such before I ever started on the motor. So maybe you can run vacuum, maybe you can't, depends on what and how your motor is built.

427 side oiler, iron heads, 9.6 to 1 compression. Side Oilers were NEVER designed for "quench", you have to order custom pistons to achieve that. It is way high on the list of things to do if your building an "Engine Masters Challenge" type motor and are forced to run pump gas. Quench, among other things, greatly reduces the possibility of pre-ignition. More compression, lower octane, still big horse power, it can be done!