I am ready to start using my 225 Slant but am wondering if this engine's valves are compatible with unleaded fuel. The engine has never been opened so the original 1968 internals are there, Thanks.

The 1968 heads have the softer valve seats for use with leaded fuel. It will work fine for a long time with unleaded fuel, so long as the seats are in good shape now. The unleaded fuel will cause the valve to bump the seats back into the head a bit, and as such, will make valve adjustments needed more often.

Ideally, you would pull the head at some point, and redo the valve seats with harder ones, and then put a nice 3 angle or 4 angle valve seat grind on it.

~THOR~

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1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Would any type of additive work.

I've heard that they "help" but in the overall scheme, it's just an extra expense you can do without. I wouldn't worry too much about the valve seats right now. Just make sure the valves are adjusted correctly (I: .012, E: .022) and go about your day.

~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Thanks.

Don't waste your money on additives; all they do is drain your wallet and shorten your spark plug life. Just run it for a nice long time until it's time to do the valves, then do 'em. See here for more detailed information. In the meantime, keep the valves adjusted, and you may want to look over the tune-up parts and technique suggestions in this thread.

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