Oh it's rod knock, when I first rebuilt the motor I checked 3 of the four sets of bearing and the set I didn't check was either bad or wrong and they scuffed up the crank. When I replaced them the crank was within .0005" of being out of tolerence. I took the chance that it'd be okay and I was wrong. After about 200 miles it started knocking again. I'm hoping that the thick oil will fill the void left between the bearing and the shaft. I'm not planning on taking the car far or to the track or anything. I had a friend die in a motorcycle accident a few weeks ago and there is a memorial car and bike show planned for him, I'd just like to get the car there and back home. I've got another motor built and waiting to put in the car and just haven't had time to put it in.