According to my 1940 Chevrolet parts book............a model FC is a STANDARD SERIES , having a wheelbase of 109 inches. General data.== Body styles made : town sedan, sport sedan, sedan, coach, cabriolet ( convert ) , sedan delivery. stock tire size is 5.25 x 17
I think the standard series had the beam axle with elliptical springs ?
the master series had the knee action system.
mike