I have an 81 RX7 with a street ported 12A that I run with NASA. I am having a problem and can not figure out what the cause is. When the RPM's get to 7000, it is like I am hitting a rev limiter, and the engine starts missing. My fuel pressure does not drop, and all my gauges appear to be fine. I have a weber 45dcoe carb on it, and it has been tuned on a dyno with no RPM probelms. I have changed spark plugs and plug wires and cleaned the fuel filter, and also have changed the distributor cap, but nothing has helped. I do not know what else to check or try. Anyone have any ideas?