It is still rich. 12.5:1 at 3550 rpm may not be/look so bad if you can get the AFR closer to 11 to 11.5:1. I know I almost shit my pants when I got our Procharged TBSS tuned from 10:1 to 11.5:1 AFR - it pulled that much harder to redline. Obviously depending how much meth you are spraying will have implications on your target AFR, as it is typically run that much richer vs. gasoline.