I have heard the opposite to be true, that Merc kinda under rated the HP, or at least was close to the true HP they claimed, but the other makes tended to over estimate? Im no expert, this is what my engine builder told me...he builds and races Mercs. I know when he built mine he 'tweaked' it here and there....supposed to be around 210hp or so, but who knows. I would love to find a 3.0L 250 to rebuild.
I dont know when Wellcraft changed the HP capacity, I believe the earlier years were 235 max, mine ('78) is 200 max
Im sure someone will chime in with a bigger brain than me
