36 or 40 hp gearbox

I have been offered an engine stand with a a bellhousing and starter not bad actually has a small fuel tank and filter and an ammeter, oil light and starter button.
I dont know however if its a 36 or 40 HP bellhousing or even if they are different.
it has a part number which is 002 301 107 A
Anyone know ?
Thanks in advance Mitchell

36 and 40 are both same size and take 6V flywheel will also fit a 6V 1300 or 1500 engine

the bell housing chages slightly bigger when you go to 12V engines and flywheels

002 indicates a bay window bus.