I have what i believe is spark knock. The sound is a metalic knocking scratching kind of sound. It only happens when the car is started, when i put it in gear or when i run over a pothole or bump. The motor is out of an 80 sport coupe and I rebuilt it stock except with forged pistons and a slightly larger cam. I have zero low end power. The car won't break 1000 rpms going uphill but when i get her on flat everything goes fine once i get up to 20 mph or so. I don't have a pevc valve in at the moment. My stock one is shot and i'm in the process of rigging in a new one. Please help.