Hi frat: Just my biased opinion (because I own a 93 Proline 2950, with twin I/O's), but I'd suggest looking the transom and bilge area stringers over carefully for signs of water intrusion, and if there are none (or just a couple of bolt or screw holes), I wouldn't be too concerned. If you buy the boat, remove all the through-transom fittings, and let the holes dry thoroughly and reseal with 3M 5200 or similar (or silicone caulk if you might need to remove the fittings later). Even though the transom and stringers have a wood core, They are fully encased in fiberglass, and there are a lot of boats out there in all brand names and configurations that are older and with wood cores. If cared for correctly, there is no reason they shouldn't last a very long time. I think the fear of wood cores is over exaggerated -- If the boat wasn't fitted out or cared for properly, it is an issue -- but it is a "boat by boat" issue, not a generally bad thing. (Kinda like a comparing one car with another -- was it taken care of)??
On the topic of being too big -- There are no "too big" boats in the SF bay or ocean...
I think the 2950 is a great boat -- wood core or not.
