Longevity to me would imply:
- precision machine work
- measured rod & main journal clearances to select the oil viscosity that is best suited to them
- 4032 forged pistons (I don't like cast or hyper-casts) for tight cold clearances and reduced hot expansion
- file-fit rings, NOT generic "drop in" rings where the gap sizes are like rolling dice
- plate-honed bores to allow fitting the pistons at the proper clearance
- oil system mods along the lines of what others said before
- smooth cam lobes (hydraulic or solid) that won't beat up the valve train and don't require heavy spring pressures
- building the engine w/ reasonable quench/squish to help offset detonation with "street octane" fuel
- getting the tune dialed in to keep the car out of any detonation
- getting the carb dialed in (along w/ during the tuning phase) to make sure the engine runs clean and doesn't put excessive raw fuel down the cylinders

I dunno... just a bunch of things that came to mind.