1969 OMC gears, are they case hardened?

[Ntr]

Hi all, I have some slightly rusted gears. I would probably use them and flush the oil a few times but just thought I'd ask if they are case hardened or not and how fast they grenade if so.
Thanks in advance.

 

[alldodge]

All gears are hardened otherwise they would wear out real fast

 

[Ntr]

All gears are hardened otherwise they would wear out real fast

My question was about the type of heat treating whether they are case hardened or through hardened or tempered.

 

[racerone]

Is this a 1.5 HP or the 115 HP V-4 engine ?