Just installed an Air/Fuel Ratio monitor, and have had a few longish legs to do some data collection during leaning (painfully slow leaning to evaluate injectors and learn what AFR is telling me). Lot's of raw data to wade through, as its collected by hand from my VM-1000
My first peek at this data seems to correlate well with the charts and numbers Dan shared here. Best power, roughly based on cruise speed during leaning, occurs about 12.5:1, Peak occurs in the mid- to hi- 14:1 range (14.5 to 14.9) and my motor starts to grumble a bit and speeds drop off markedly just before reaching 16:1 (the top of the scale on my AFR monitor). I'm going to try to hand-jam this into a few spreadsheets, and will be happy to share what I come up with. The sensor is on one side of the engine versus each cylinder, the data is eyeball collected, and the AFR reading jumps around a bit, so it may not be at the super-fine data level you may be generating...but if its of value, happy to share.
Its giving me some good data on injector management too!