In early 1921 the Chevrolet Brothers developed a special cylinder head for the Model T Ford.  It utilized overhead valve technology, and it increased the volumetric efficiency of Model T engine.  Whereas a stock flathead Model T would make approximately 17 horsepower, the same engine equipped with the Chevrolet Brothers "Fronty" head would make over 30 horsepower.  Priced at $100.00 it was the ultimate trick hotrod part for the Model T Ford.  A number of variations of this cylinder head were made available by the Chevrolet Brothers, with different compression ratios, dual plug ignition options, and overhead cam racing set ups.  Following the success of the Frontenac race cars at Indianapolis, the Fronty cylinder head became a very popular aftermarket accessory during the 1920's.  Below are copies of original catalogs produced by the Chevrolet Brothers for promoting their special cylinder heads & speed equipment.