Ah, so he used the spec for the wrong engine, not the wrong vehicle (well, wrong vehicle too I guess). The way he said it made it sound like the 4ZD1 engine in a different vehicle had different specs and I got to thinking how my engine didn't start out in my vehicle. I guess I was grasping for a reason for the burned valve. The reason is likely infrequent valve adjustments with a possible overheat in January thrown in for good measure. Anyway, it's all clear now. I need to go find the feeler guages.
Thanks!

1986 Isuzu Trooper, 2.3l, 119k miles when acquired 3/1996, 231k at time of death 9/21/03.
1995 Jeep Cherokee Sport 2-door 4x4, 4.0l, 5-speed, 85k miles when acquired 11/2003, 138k now.