The rear end is original, however it clunks going either way, from Park into gear, or neutral into gear. Not so much a "clunk" as a "jump" much as if the rpm were too high, but I don't think a couple of hundred rpm should make that much difference, and I'm not sure the specs are necessarily correct for the 235hp engine. 500 rpm is a low idle for any engine, and the 235hp has a hotter cam and much higher compression than the two-barrel engine. Once the car is in gear it runs, drives, and shifts smoothly.
