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38 coupe · 07-10-2025, 05:13 AM

Ford had good hard valves suitable for unleaded gas in all the flathead V8s. The valves before 1949 had an odd design with a widened tip where they contacted the lifter and a split valve guide to make assembly possible. The split guides work, but allow some oil to be pulled up the intakes. The later guides and valves make assembly easier and burn a bit less oil. Many flatheads got the later valves installed over the years, I would look at what is in the engine already before spending money on new parts you may not need.

Ford had good hard valve seats from 1932 through 1950, then progressively eliminated the hard seats.

A Columbia rear axle is visually different from a standard axle, your car probably does not have one. Most 39-48 Mercuries came from the factory with 3.54 ratio ring & pinion, a favored higher speed gear set in the Ford crowd. Also, Mercuries from 1939 through 1941 had the drive shaft and pinion gear made as one part, making rear axle ratio changes more difficult. I recommend getting your car in driving condition and seeing how everything feels before making plans to change stuff. Driving the car will inform you what you needs to be repaired or changed.

07-10-2025, 05:13 AM	#50
38 coupe Senior Member Join Date: May 2010 Location: South Texas Posts: 2,137	Re: My new project. And introduction. Ford had good hard valves suitable for unleaded gas in all the flathead V8s. The valves before 1949 had an odd design with a widened tip where they contacted the lifter and a split valve guide to make assembly possible. The split guides work, but allow some oil to be pulled up the intakes. The later guides and valves make assembly easier and burn a bit less oil. Many flatheads got the later valves installed over the years, I would look at what is in the engine already before spending money on new parts you may not need. Ford had good hard valve seats from 1932 through 1950, then progressively eliminated the hard seats. A Columbia rear axle is visually different from a standard axle, your car probably does not have one. Most 39-48 Mercuries came from the factory with 3.54 ratio ring & pinion, a favored higher speed gear set in the Ford crowd. Also, Mercuries from 1939 through 1941 had the drive shaft and pinion gear made as one part, making rear axle ratio changes more difficult. I recommend getting your car in driving condition and seeing how everything feels before making plans to change stuff. Driving the car will inform you what you needs to be repaired or changed.