What are the main differences between the gen 1 and gen 2 drives. I have an older (1987 Wellcraft Cruiser) that currently has an Alpha 1 gen 1 with the lower unit and the gimbal ring that are pretty eaten away from saltwater over the past 7 years. Originally I was just going to replace the lower unit, gimbal, bellows and call it a day but with the age and the fact that the boat has been in saltwater for the past few years thinking of refreshing everything. If I do that would there be any advantage of going to a Gen 2 over the Gen 1 drive?

Realistically for what you have, no. The Gen2 is a little more hydrodynamic, but I dout you are achieving those speeds. It also has an integral speedo pitot.

Unless you can get the whole transom assembly for less than replacing your gen 1 stuff, I would stick with the gen 1.

No offence to ya but just a quick FYI. There is no such drive called an Alpha 1 Gen 1. There is a Alpha 1 and a Alpha 1 Gen 2. Alpha 1 made up till '90. Alpha 1 Gen 2 started in '91 and was upgraded in '96 and again in '98. Just let'n ya know so the parts guy don't look at ya funny when you ask for a Alpha 1 Gen 1 part! Just joking but seriously if you want a lot of info or replys on Alpha's check out iboats.com. It's all Alpha gurus over there that can tell ya anything you would ever need to know about them.