Jim, an average of three 0-60mph times per fuel mix would have been more indicative of performance gain or loss. Easy to do with a copilot. Also some notes about the weather conditions, time of day, temp, initial and total timing and some indication of the mechanical advance curve, jetting, cam, stuff like that so we can try and relate some of your data to what's on other cars. Obviously the tests weren't all completed on the same day unless you did an awful lot of driving that day.

If you are running the 068 cam, your set-up will likely be the most demanding regarding octane in comparison to the other 400 engine combos.


If your charging system is running that high (18-24 volts), either you need a new voltmeter or you'll be frying batteries like crazy. Proper charging voltage is 14.7 volts.