Bravo upper lower combos
 

Has anyone ever mated a newer bravo upper that has the small oil hole next to the water inlet chamber with an old lower that does not have the oil hole but has a full circle water inlet at the joint? Question is can you thread and plug that small oil hole so the gear oil is properly maintained or will that cause other problems?? Thanks. Tom.

yes you will have to drill and tap the new upper and install a plug 1/16 npt

Thanks. That is what I was hoping

Curious if you know more is that oil channel a return for oil or is a feed to get extra oil up to the yoke bearings as I see that is where it leads? (Guessing Merc added that channel for a reason on the newer drives)