Sorry wrenchinrick, I'm not trying to highjack your thread but it does brings a leaded additive question to mind...

First of all I'm not a motor guy and I need some schoolin'

I have a '69 Ford 302, major rebuild in '76 (last run in '85) Ran on regular (in California), Motor was freshened but didn't really need it. Heads were ported, roller rockers and little higher performance cam installed. Valves and seats were OK.

My question is do I need to run a lead additive? And what will happen if I don't.