The longer connection rod offers better top end and midrange power as it dwells longer at TDC, allowing the engine to build better pressure to push the piston harder. Please make a note that either a longer rod or a shorter stroke crank will lower the squish velocity.
So there for you will have to recut the head
which you would be doing anyway if you were modifying the engine in such a way

The benefit of the long rod was shown in the jetski engines i build to race
there is less side load at any time and this amounts to less friction and better mechanical efficency
the upside of all that = Horsepower