[blykins]

Cam intake duration has a lot to do with what you can get away with. However, with 12.5:1 SCR, I don't think you can make it on race gas. You can play with DCR to a certain point, but after that, efficiency starts playing a key role. At some point, the engine is gonna be efficient, and you're gonna see a true 12.5:1 SCR.

If you're sick of mixing gas, there may be a few others things you can try to get the ratio down.