Also, keep in mind that changes in nitro content will change engine timing. I don't recall what direction it goes.. hotter advances or retards.. not sure, but it does change timing. Because the fuel burns faster, it will ignite earlier which is similar to changing the timing. This can and will effect both engine heat and performance. Sometimes, in a good way, other times in a bad way.

Best to stick with what the manufacturer recommends, or get what you can and see how it performs, and stick with what does the best job for you.

DS.