The following is an article of George Riley's tips on building a 100 MPH Model A, as published in Ford Dealer & Service Field magazine in September 1931. Riley also published a similar compilation in a booklet I believe called "Building the 100 MPH Model A Ford.
The Riley two port cylinder head was an overhead intake valve "F Head" configuration.
Follow this link to see an original 1930 Model A Ford Riley Valve-in-Head Brochure on Ford Garage.