RPM cut out
 

I have a generation V 454 wich i have added vortec heads and edelbrock rpm intake. When I rev to 4200 rpm it cuts out like there is a rev limeter or as if its not geting spark and does not want to fire. It does not quit just starts to gargle at 4200. I have new plugs wires cap and roter and coil. Runs perfectly till I hit that rpm. I am stumped. I have checked all fuel problem possabilities. The spark arestor cover says RPM max is 4200 to 4600. IS there a rev limiter? I there an easy way to disable it? Any Ideas would help, thanks..