This the long stroke and restrictive exhaust ports, high RPM is a no-no. My motor was a good street engine, kept the 10.6 compression, cleaned up the stock heads, aluminum intake, good headers, and paid ALOT of attention to the carb and ignition.
Put on the best aluminum heads, a good torque cam, and don't spin it over 6000. Starting a hot, high-compression CJ is no picnic.