[juke joint johnny]

Where was your friends Model A built? If it is a European car some of those had the small 3" Bore engine
.Look at the cylinder castings on the side of the engine if there is a large gap between the cylinder outline on 2 and 3 cylinder about 2" then it is the small engine .
they also had 4.55 rear axle ratio from standard the larger engine had 3.78 gears