outboard to sterndrive

[6buoys]

what do you guys think about changing an outboard to a sterndrive . being that i have an alpha and mercruiser 140 already .

[bigeasy1]

It's usually the other way around.(Stick with the outboard)

As someone who prefers an outdrive for what I do(great lakes fishing),I'd say if you're a saltwater boater,I'd stick with the outboard.
What size is your hull? A 140 is not even close to enough power to move a 23' with any authority and although I have no experience with the 20's I think it would be low for them as well.
I don't see any savings in switching to an outdrive,you will have to fabricate a whole new bilge/transom area,along with engine beds and a motor box.The work and cost of materials would negate any savings by using the I/O.

You will also eat up cockpit space with the motor box hump,which is not all that serious in a 23' but it is in a smaller hull.
You don't mention if you already have a good running outboard.The fact that you already have the Alpha drive and engine,still doesn't make it a good choice in my opinion.
Sell the Alpha drive and the 140 engine and buy a good running late model outboard,it will be far less costly,than completely changing the hull,and I think a much better choice.

In my situation,the I/O is a better choice,as my use is all fresh water ,we only troll,all our fish are netted off the back,so the clean transom is better for me.Inboards and I/O's are also more common on the great lakes,and the boat yards there are far more accustomed to working them,so service is easier to get for them.I can also do most of the work myself,being that it's basically a car engine.

As much as the I/O is a good choice for me,if I was restoring a hull that was setup for an outboard,that's the way I'd leave it especially if you're use is salt water