Hamilton Cams Head 12V Cummins 1989-1998
All of our products are tools to remedy an issue for a particular application. This head is no different. It greatly improves airflow. To do this, larger ports were needed, which slightly reduces performance below 2,500 rpm. If lower compression or large cams are used with this head, low rpm performance is degraded further.If you are running a small or stock turbo, buying this head will be a waste of time for you. Your turbo is the restriction, not the head. If your head is the restriction in your setup, this head will make a major difference. I have heard people say that their hand ported OEM head with stock valves can out-flow our head. That is not reality, but because of poor testing methods it might look the case. When a head is flowed in a bore other than what it will be running and in a different position(valve to bore), you can skew flow numbers by over 50CFM. When you are considering buying a head from a person, ask how they flow test the head. If they do not flow it in your bore size and with a fixture to locate tIhe valve correctly in the cylinder, then the flow numbers are not valid.
If the cylinder head you are currently using is the limiting factor in your engine, we have seen 20-300HP gains. If you identify an issue with our head, we will replace the casting at no charge to you. Please show proof of purchase. We are not liable for any other costs incurred do to custom machining.