Engine is limited for aftermarket products without spending a couple of mortgages. I suggest having larger valves pur in the heads and turbocharging it. With about 7-9 pounds of boost on a hill or passing somebody, it will do the trick. The 534 has pretty small valves for as big of an engine that it is. The cam limits the RPM band. I don't think I've ever seen a stock one go past 3400. So might as well get some air into it for the power band you have.