Actually, tetra-ethyl lead also provides a lubricating action for the valve seats. Octane rating makes no difference until you get low enough to get into 'knock' country. Also remember, an engine can be knocking long before you can hear it.
195? Chevy 3800 dump truck 1973 Chevy C30 cab and chassis 1987 Suburban 3/4 ton 6.2L Diesel
