Ahhh, this is something I've been thinking about as well, as the time draws near when I'll have to drain & replace the oil in my 4JB1-TC.

I've been planning on taking the old one down to the local parts warehouse (not one of those national chains, but a distribution house for a bunch of local stores - they've got lots & lots of parts...) to try and cross-reference the number or just match it up with something.

Would you mind posting the info you've got on the Isuzu numbers (and maybe where you got them)?

Thanks.

If I learn anything I'll be sure to post it.