How Much Gap?

I have gapped the plugs as far as .060, but power fell off on a 8.5-1 engine.
Good results have been found through trial and error. Best result I have found is right around .045. At .050, it should be considered pushing it as far as runing well for max mileage and power. This for both the stocker and performance 360's. (8.5-1 & 11-1 engines)