My answer will be contrary to most but based on personal experience. You pull a trailer that changes things, long life will come from a valve train with relieved pressure/ loads, lower heat (compression & cylinder pressure down), and excellent ring seal. What does it take to go there? A 113 from stock cylinders bored +.060. A cam with mild ramps and added exhaust duration. If 117 is on the plate, ok this is a full engine job, bored cases not the drop-in kits. Remember you said 60k reliable miles, that is where I am going. Compression on the conservative side. Heads need new guides and a good valve job plus dual springs that are lighter than stock. High quality lifters. Crank needs to be reworked at minimum, an S&S crank, better. Use head fans to cool the engine. Add a higher capacity clutch. Use the latest rev compensator. Have a proper tune done. Consider a smaller front pulley to lower gearing.
The whole gamut of things the internet says that are needed, many are not and just oem parts will be fine. Lifters are a maintenance item still, 30k miles and gives a look at the cam chest then.