if you think that the 4g63 is unreliable, you are in for a rude awakening.
4g63>>>>>>>>>>>>>>>>>>420a in terms of reliability. it isnt even close. i have owned both, so i am talking from experience.
420as love to blow headgaskets, have TERRIBLE wiring harness problems, and difficulties with sensor reliability.
crankwalk happens in like 4% of 97-99 engines on average. and, it generally happens around 60k miles. so, most 97-99s have more miles on them now, so they are past the “primary” time that crankwalk would happen.