Vacuum advance needed for cam break in?

Get a bunch of timing on it. If the slowest speed you plan to run the engine is 2K get at least 35 on it there and let it go. Watch temps and leaks. No load, usually no issues with detonation

Unless you have a fast curve, all in at 2K, you may think you have a certain number of degrees on it because of the intended total number. If that total number isn't in until 3K, you aren't close to that number at 2K.

To me the vac adv is a potnetial variable. if you change throttle speeds and for some reason the vac drops below the can activation level, all that timing is dumped out. Make that stuff static, just twist the timing in. 40* is fine too.

Running rich is not good either as the unburned gases continue firing off in the exhaust port/system creating more heat.