Check for water on dipstick. If none, pull distributor and use engine oil primer. Drain al the old gas. You may have to clean out gas filters. If water in block, check for block cracks. If cracks, look for another motor.
on Alphas, there is another seal on the other side of the gimbal bearing. Water can get into bellows by coming via engine hatch via gravity and landing on shaft exposed between transom and coupler. I had a bad seal one time that did this to me.
Gimbal ring bushings worn???? Noise only coming from outside????? Spray a little WD 40 on each and try to work in oil. If noise is reduced, then replace bushings. At least you will know if noise is coming from them.
If v8s were pulled there is a chance that some rear motor mount parts may have been dislodged and fell in bilge. Happened to me too. If it does, you will never align anything.
A number of headaches may await you. Pulling drive and manually inspecting bearings and u-joints is a must. But, that's an old boat and may have ROT in transom or stringers which will cause motor to shake when under a load. MC's engine mounts are strong. Closely examine motor while someone else...
