Short vs Long Shaft for 4hp

[Beakster]

Hi all,

I am looking for a Johnson 4hp to put on a small inflatable 4 person dinghy. I expect I need the short shaft version of the motor. When looking at used motors online how do I tell if its short or long shaft if the seller doesnt specify? Do they have different model numbers?

Thanks

 

[Nordin]

OMC smal OB 60-70.es has an extension part for the long shaft.
Easy to see, different between short and long shaft is 5 in.
Short shaft 15 in long shaft 20 in.
You measure from transom clamp to anti cavitation plate.