Re: gimble replacement Alpha1 Gen 1
The "drilling holes" method is fine.........I did it prior to this season on my 1991 5.7 Alpha ("Gen I") to replace the Upper Swivel Shaft and its seal.
I had no easy way to remove the engine. I was able to replace the upper & lower bushings for the Upper Swivel Shaft, as well...........difficult, but I highly recommend doing that (although you may have greased bearings and maybe you don't need to, then).
I also replace my Lower Swivel Pin and its bushin, and I even used Resiweld (then sold remaining Resiweld on eBay).
You can then replace any/all other bolts/nuts/bellows/shift cable, etc.........give your whole transom assembly a re-build.
USE THE JR MARINE STAINLESS STEEL UPPER SWIVEL SHAFT...........they're awesome!