Keith---It's not necessary to use octane booster under most
circumstances. I don't think the "Lead Substitute" is necessary, as I
have found no obvious valve seat recession after using nothing but
unleaded for at least 100,000 miles. Even with the mildly stiffer valve
return springs.
The later, lower compressioned engines should run without knocking with
the 87 octane, using the stock ignition timing. The recommended higher
blend was for a formula that measures the octane rating differently, and
most likely for the earlier TR's. Assuming the head hasn't been
significantly milled, if you hear more than occasional pinging under
acceleration with the 87, check the timing. Going to the next level of
octane is always an option, if necessary.
Dick
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