(1) Metal alloys used in the engines are much better these days. When was the last time you saw a car with a blue cloud behind it? When was the last time you needed a ring and valve job?
(2) Synthetic oil is a godsend. Use it religiously.
(3) Electronic fuel control is another godsend. Don't be cheap: replace every sensor every 80-100K. 1/10 of a volt variance in a sensor's performance makes a big difference. You've gotten you money's worth out of them and they are cheap. Replace your injectors too, and while you're at it, replace the coil packs.
(4) Replace your fuel pump every 100K, no matter what. It's like putting an 18 year-old's heart into an 80 year old man. You'll notice the power curve extending up another 1-2K.
(5) Replace your intake gasket at 100K. Don't argue about it, it leaks no mater what you believe, and you'll notice the difference.
(6) Finally, add one or two more grounding straps from the negative battery terminal to the chassis and the engine block. This is cheap and easy and has a big effect (I find). As noted before, sensors work on 1/10 of a volt. Most engine sensors pick up the negative lead from the block, which is grounded in only one spot, and this gets corroded and fouled with grease over time. If that connection is not 100%, your sensor will not function as it did when the engine was new. Adding new paths to ground keeps the sensors working as designed.
bttt