Honestly you have better heads than most who tell you they arent enough.lol its comical.
I ran j heads 186cc port flowing 280's ...the motor was a bad ***. Destroyed everything on the street. It had no issue pulling into 7k.
I blew the cylinder wall out in my 1978 block however. Building the short block now, same heads and cam...carb had a loose throttle shaft-sucked air and wen lean on no.5 which is the closest cyl to it.