"A 17 footer might be a touch
"A 17 footer might be a touch small for the V-8, but it depends on how much freeboard you have at the stern. The small block V-8s are not that heavy really. I replaced by V-6 with a 6.2 V-8 and added less than 100 lbs net weight. In fact I don't notice my boat sitting any lower in the water at all. But there is a huge performance difference. I went from 180 hp to 350.
In terms of fit, the back engine mounts will fit right up to your current Alpha transom plate and bolt right on. They are all the same. The drive shaft splines are all the same. In fact the Bravo engine mounts fit an Alpha transom, and the shaft splines are the same. Any new engine will likely come with new front mounts (mine did) that bolt right to the main engine side rails in your engine bay. You can check all the dimensions with the drawings available on Merc's website, or I can give them to you if you like. You will need to change the current exhaust downpipe to a V-8 Y pipe. Again, no big deal, it will bolt right up to your Alpha transom plate. Or do like I did, go side exit exhausts. They sound great.
Rod"