How come my CRX cuts out at high rpm?

I have a 1991 Honda CRX. It has a 1.5L (D15B2) and it has like 196xxx miles on it and it's automatic by the way. When I step on it, it accelerates fine but when it starts to get to the high rpm range, it starts to like cut out. I've changed my plugs and wires and also the head gasket. Any ideas on what it could be? The car starts right up and the car also vibrates at in gear at idle but the idle is fine. It's not too low.

Bad fuel filter, bad fuel pump, clogged fuel line, bad exhaust valve guides, bad cam springs, clogged up air filter, among other things…

High RPM? How high? If you're hitting 6 grand then chances are you're hitting the rev limiter. It prevents you from OVER revving the motor and damaging it.