I use both the 50gr Titanium adapters and 75 gr TI adapters for my Abowyer Wapiti's. The 50gr are 21/64" in diameter and fit perfectly flush with the end of the Abowyer broadhead ferrule. The 35gr TI adapter is 5/16" diameter and is going to fit all the way in the ferrule with some ferrule hanging out past the end of the adapter. The 75 gr is a full 11/32" diameter and the Abowyer broadhead ferrule won't quite come to the end of the adapter.
The ferrule on the Grizzly head is slightly larger in diameter than the Abowyer so the ferrule will hang out slightly (maybe 1/32")past the edge of the 50 gr TI adapter, which doesn't bother me at all as my shafts are smaller than the diameter of the adapter. It would hang out quite a bit past the 35 gr adapter and sits perfectly flush with the 75gr adapter.
As far as gluing, I agree with JimB...the more surface area for glue the better.
Hope that helps.