During the 20s, 30s and 40s, the availability of inexpensive used Model T Fords and man's (boy's) instinctive "need for speed" inevitably lead to the creation of the Hot Rod.
The first "Rods" were nothing more than an old T, the body and muffler removed, with a makeshift seat bolted to the frame. These "doodle bugs" were raced around town and down dusty country roads until in the spirit of competition and public safety dirt race tracks appeared around the country.
The sport became so popular that literally hundreds of companies sprang up to provide racing parts and nifty accessories for the popular past time of dirt track racing.
Among the most desirable accessories were high compression overhead valve and over head cam heads. Rajo, Fornty and Roof were among the most popular. The Galivan dual overhead cam (DOHC) head was a late arrival and was know for its hemispherical combustion chamber and large ports.
Joe Gemsa, perhaps one of the most famous builders of fast Ford engines, custom built his own speed equipment borrowing ideas and tweaking them to give his clients an edge. The Gemsa head shown in these photos was patterned after the winning Galivan DOHC design.