454 mag. breaking up at higher RPM
 

Mostly stock gen v motor. Recently started this, sounds like it is hitting a rev limiter around 4000 rpm. Used to run cleanly to 5000 rpm. If I hit my trim tabs at higher RPM the engine drops about 200 rpm. If I bump the power trim on the outdrive the engine will miss. I have two newer batteries with fresh charge and my dash gauge says my alternator is putting out 14 volts. Anyone have any ideas? I am thinking electrical?