Ok, so I got a used semi used set of aluminum pro-comp roller rockers a while back on a trade. I was planning on using them in a low buck 5.0L for a 4 banger conversion I started. I called Pro Comp and asked them if they could send me an instruction sheet for installation since they did not have it avalible online and they told me that do not give out instructions with their product that they expect to take the product to a licensed pro for installation. I told him I never heard of this and that every other set of rockers or even heads had some paper work come with it. Now I know why I found so much negitive information on Pro Comp on the net and this is most likley why their products are so cheap.