Well i have had some time to take my 300zx apart and eliminate some of the possible problems. It has now become apparent that the bottom of the motor is toast some where. After switching the lifters and inspecting the valve train the knock will not go away. So there is a fresh JDM motor on the way that I will transplant into her to get her back on the road. Currently, the motor is out and on the motor stand and will be posting a few pictures up soon. as i dissect the bottom of the motor for the problem.