few questions with my new motor

[fultz416ex]

i am getting a 425 kit from LRD for my 400ex. i got a J &E piston that is 12:1. should i run 50/50 mix or should i run straight race gas? also what should i start at with my jetting? i live in central indiana, i have a mild port and polish, uni filter without lid, white brothers e-series without discs but with turndown endcap, and a hotcam stage 2 cam. any help with that. thanks
travis

[Bad Habit]

I would go with straight race gas. It's not gonna cost much more per tank compared to the 50/50 mix.

If you have a stock carb, I would try a 170. It will probably be a little too rich, but it's easier to tell when it's rich and just back down from there.