When installing newer style bravo 3 gears in an older style case, the changes required are the thinner drive gear shims, but what other changes are required to make the swap?
A previous thread mentions a top cap modification

You have to use the thinner drive gear races that are .030 thinner as well as the shorter inner races for the driven gears that go on the tower in the case and top cap

Also must use new style thrust bearings and new style one piece clutch bearings,and the shorter tower races must be installed to the correct depth on the towers.