the leaded fuel with eat away at the o2 sensors over time. I have never experianced it myself. some of the stations arround me have leaded 110 sunoco race fuel. I would do 1/3 ration of race per reg fuel and do logging to make sure you have enough race in it.

if you were to buy from vp, the best to get is the vp import fuel. or oxygenatied fuel.