I have a 1967 Ford Galaxie 500 with a 390 engine, and have had it for about 2 years. In that time I‘ve put about 3000 miles on it, all without using a lead additive in the fuel. I hadn‘t even bothered to think if I would need it or not. Would I have wrecked the valves already by doing this, or might I not even need it? I don‘t have much history of the car, so I don‘t know if it has the hardened valve seats or not.So basically, if I‘ve made it this far without doing anything, am I pretty much in the clear, or should I still switch to the lead additive since damage might take longer to manifest?
it will run fine for now, but yea, use lead substitute in every tank of gas. the real fix is to get hardened exhaust seats installed in the heads, but you're looking at time and bucks. also, what you should use is a zinc additive in your oil at every oil change. modern oil does not have zinc in it (they removed it to help protect the catalytic converter), and you will round out the bottom of your flat lifters; also expensive to fix.
