From what I've found these engines seem to share the same block but different cranks. From what I've found these were built form 1913-1915?

9hp Honest John

7" Bore x 10" Stroke

290 RPM

Flywheel Diameter 37"

1900 lbs Shipping weight

12hp Big Reliable

8"Bore x 11" Stroke

280 RPM

Flywheel Diameter 40"

2500 lbs Shipping Weight