Harry Miller was an artist. His preferred medium was race cars—complete race cars built from the wheels up. They cost upwards of $15,000 (almost a quarter-million dollars, adjusted for inflation) and spent most of the 1920s dominating America’s tracks. Unlike such contemporaries as the Chevrolet Brothers, Miller largely kept out of the speed-parts business. He briefly produced a cylinder head for the Ford Model T, but didn’t pursue that market further, supposedly saying “I’m not going to make any more of those heads for the Ford. Those Ford guys don’t have any money anyway!”
In 1929, though, Miller sold his business and retired mere weeks before the beginning of the Great Depression. Unable to stay away, he came back in 1930. Thanks to the terrible economy, however, he had to produce products far less exclusive than his famous racers of the previous decade. One of the things he marketed in conjunction with financial partner George Schofield was an overhead-valve conversion for the Ford Model A. The cylinder head had been sketched up by longtime Miller collaborator Leo Goossen in 1928, shortly after Ford began Model A production.
An overhead-valve (or valve-in-head, as they were often called at the time) design, the Miller head moved both intake and exhaust valves out of the engine block and into the head where the air flow would be freer and more direct to the combustion chambers. The port arrangement was identical to the original Ford, which allowed the stock intake and exhaust manifolds to be used if the buyer desired. The distributor hole was in the same spot as well.
Miller only produced this head very briefly, although Cragar (yes, that Cragar) took over the design and continued it for several more years. Original Miller-Schofield heads like this are a rare find and they still add a lot of pep to a Model A.
All of that is perhaps a long way of saying that a head this special deserves a build to suit. Unfortunately, that’s less common than you’d think. A lot of Model A and T “speedsters” are really just some seats strapped to a stock frame and it seems like when you see OHV conversions for these engines, they’re often on stock-looking closed-cab pickups. All of that is fine and dandy, but it’s not for me.