WE went to a company called HOT CAMS they have a auto decompression exhaust cam and a nice intake cam. We just installed a set in our 426 it was simple. We replaced the timing chain with the cam swap. I am sure someone else is making these cams for the 426 but these are all we could find. We did not have to do any other mods other than resetting the valve lash. There is a very noticeable power gain throughout the rpm range.