Johnson 120/140hp ?

[PapaMaC]

My 1989 Johnson v4 120hp Looper shares the same powerhead/mid-section/lower unit/etc. with the 140hp. Everything I've seen shows that there is almost no difference at all other than intake manifold and possibly carbs. Does anyone know for one if it's worth changing 120hp parts out with 140hp parts (will there will actually be any gain in hp?) and secondly exactly what parts would have to be changed? im hoping there will be someone on here with a bit more certainty than the other threads I found on the subject.

[83PREDICTOR]

I think it is easy to make a 120 into a 130 but requires a bit more to get 140 out of a 120. The are a few thread over on S&F that have a lot of info.