I just dropped a 13.6:1 compression 372ci small block in my Camaro. It has a 268/
[email protected] solid roller. I wouldn't dream of trying to run it on pump gas. However, at 12.5:1 if your calculated DCR is in the 8.5:1 range it might work at low speeds/low throttle. I've never run meth on a N/A combo, but I ran it on my supercharged C5 Corvette. The meth system was boost referenced and had progressive activation based on boost level. It was 'always on'. That motor had 9.6:1 static compression and I was able to make over 800rwhp on 16psi boost using pump gas and 50/50 water/meth.