Early bravo 1 to late
 

I have a pre 1991 upper and lower unit. I don't know what year gimbal and bell housing I have. Will early and late bravos fit on the same bell and gimbal housings. My point is can I put a later upper and lower on my bell housing.

Yes they fit. I have a 1990 Bravo 1 drive on a 2005 Bravo 1 Transom assembly.

Thank you for your help. I bought a boat that was supposed to have been repowered and a new bravo xr drive. I traveled about 6 hrs to pick up the boat to find it was a bravo 1. I still wanted the boat. At the time I didn't know it was a pre 1991 outdrive. No serial #s on tag.I removed the lower unit to find it's pre 1991. I already bought a late sportmaster. On SEI's website they say you can tap the oil hole and plug it. To be able to use a late lower on an early upper. I was under the impression that the oil hole is so oil can circulate to keep oil cooler and for better lubrication. If I plug the hole in the lower should I plug the hole in the upper. I am running an Imco drive shower. I want to use what I have for now until I buy a later upper. So I have to be able to open the oil hole in the future. Any input will be very helpful.