I am looking at buying a used boat that has twin mercruiser I/Os with Alpha I outdrives. Can the outdrives be replaced with Bravo IIIs? Approximately how much would it cost to replace them, if it could be done?
With used stuff, maybe the $8k that Dakota says, but even that is a stretch.
From Marine Power Service a new Transom Assembly is $2895. A new Bravo 3 drive is $4495. So that's $14780 and you still wouldn't have the raw water pumps, they are at least $300 ea. So you're over $15k in new parts and you haven't even turned a wrench.
Just understand one thing, you can't just change the outdrive, you must change the entire transome shield as well, inner transom plate, exhaust Y and possibly the exhaust elbows and hoses aft of the risers.
I removed a King Cobra and replaced it with a 454/Bravo III I bought locally out of Craigslist.
I replaced EVERYTHING OMC with EVERYTHING Mercruiser. You might be able to keep your engines, trim pumps and steering. but you would replace everything else.
I paid $5k for a used 125hr 1997 engine/drive/everything out of a totaled 24' Bayliner (hit by a tree in a wind storm).
2 dealers told me that they would have sold that (used) package for $8k-10k. I WAS VERY LUCKY. (One dealer had a 400hr (salt) 2000 5.7L 300hp MPI Bravo I for $7000)
I have since watched craigslist for similar systems for sale and have never seen anything even remotely comparable in price....
There's a LOT of boats out there now-a-days for sale.......around about OCT/NOV they'll start getting cheaper as people re-evaluate whether they want to pay big bucks to keep something they don't use......you should just look for what you want and low-ball someone that wants to "off" it!
with more being more likely buy the time you buy props