NITROUS OXIDE ( nos / n2o ) advice forum

Wanting to know what fuel ppl are running,ATM I'm running bp ultimate 98 unleaded with vp racing fuel maddative which brings it up to like 106 I am thinkin of swapping over to vp racing fuel 109
Will i gain more power?an will I notice the difference

You generally only see any worthwhile improvement from using higher octane fuel if you are;
1) Runner high compression
2) Intend to raise the compression
3) Use or intend to use high power increases from nitrous

I'm running a 150 shot mate

You shouldn't need to run any more octane than the 106 you're using with a 150 shot on a mild SBC 400. Raising octane wouldn't yield much more power (if any) for the money spent on the fuel. You should be fine!

In that case I doubt you'd see or feel any improvement but the only way to know for sure is to try it.