Running a lot of ignition timing? Stock 22R w/ stock carb
 

So with my initial ignition timing unknown, my engine was idling nicely at 700 rpms (warm) and had 21 inches of vacuum.

I hook up the timing light (with dist lines disconnected and capped), and it was advanced a lot, beyond the 12* BTDC mark. I turn it all the way back to 0* like it's supposed to be, and the engine idled like crap. Adjusted the idle with the idle screw a little bit and it's better, but not running as smooth, and only has 19 inches of vacuum now. I advance it to 5* BTDC and it smooths out some, still only 19 inches of vacuum.

The carb was messed with prior to my getting the truck, so I have the mixture screw reset at 3-1/2 turns out from full-in.

I didn't drive it around before setting the timing, save for babying it around the block once, so I don't really know how well it would have run like that... but if the truck is running well and not pinging under load, is there any reason to not run more timing advance?