So I was wondering whats the purpose of the top holes on the bellhousing and side hole for? Were they supposed to have rubber plugs? Seems like a great way for water and crap to get into the bellhousing when wheeling

 

I believe those serve the purpose as a look through as well as a vent.

 

My truck has the side hole. I'm not sure about the top.

 

Both my trans has open holes.....the only hole that's plugged, is the one on the driver side....with a rubber plug. I don't know the purpose of those holes...sorry.

 

A clutch generates a tremendous amount of heat while being slipped. The holes are for cooling. Notice that they are placed in a way that would prevent much water from entering by splash. The bell housing isn't set up to be submerged though.