According to some grey-beards on the Antique Automobile Club of America website, AMOCO has been offering no-lead gasoline since the turn of the 20th century; tetra-ethyl wasn't added to gas until the mid twenties, and then it was for anti-knock purposes, not valve protection.
The various lead substitutes mentioned won't hurt; my personal favorite is about 6 oz. of Marvel Mystery Oil (also available @ Wally World!) to a 16 gallon tank of gas.
The engines most susceptible to valve damage from lack of lead are high-compression engines run at hard & at high speed for prolonged periods of time.
Are you pushing your stock 'bolt down the interstate at 65 mph for hours on end?
Many engines are ready for a valve job by 100,000 miles, lead or no, at that point (or whenever you
tear your mill down) you can see what kind of shape your valvea are in and go from there....
Be glad you're dealing with an OHV engine here... it's pretty simplt to just yank the head and take it to the machine shop.... MoPar freaks like me, with their flathead-sixes, have to find someone that knows how to do valves in them, and then you've got to send 'em the whole darn block!
Frank McMullen
