Setting Timing On a Lean-Burn

Hey guys,
I am currently working on learning how to set timing while my carb is out with @Dana, and I wanted to check some things with you guys.
1. What does the lean-burn do to timing? I have heard that it retards the timing when you accelerate but are there any other effects?
2. A friend recommended that I advance my timing in order to cure my rough idle/acceleration bog. Does anyone have any recommendations on what to advance it to? My guess is 10-12 degrees btdc....

Setting Timing On a Lean-Burn