I would like to update my flat head six engine 1947 to a modern engine with gas without lead. I have heard that it is necessary to change the valve seats to more modern ones that resist modern gas with high octane and without lead. I would like to know your opinion on this subject because the original valve seats in my car are built into the block.



Thank you

 

Ask this on the P15-D24.com forum.

 

Good Point !!!! I agree.... Cheers

 

I’ve had many pre 1972 vehicles, no hardened exhaust seats, and haven’t had any issues. Conservative ignition timing, a slightly rich high speed jetting along with no heavy towing and E-10 I haven’t had any problems. Not having vacuum advance doesn’t hurt either.