Are all TD42 the same?

It might seem like a silly question, but are TD42s all the same? I know that there are internal differences between early and late GQ and GU turbo and NA, but are the externals all the same? How can you tell the difference between them from the outside?

Thanks.

Earlier (gq) have silver rocker cover and later have a black rocker cover

Yes, pre 96 were the silver tops which were the stronger ones. (I think)

Yep but I think the black tops are still mighty strong units

Yes I agree. I would rely on at 600k km TD42 over an unknown ZD30 any day.

Do all the peripherals (alternator, starter, ac comp etc) interchange? Didn't one of them have a separate vacuum pump to the alternator?

I bought my 90GQ td42 a few years ago. The odo had stopped working at 520k an the fella I bought it from said it stopped working shortly after he bout it a 2 or 3 years before so got no idea how many k's. He was a teacher on community lands in the middle of OZ so dare say shes done quite a bit over what's indicated.

Mine runs engine oil through the alt but dunno about the rest of the accessories

I thought I read somewhere that some of the GQ TD42 have the vacuum pump on the back of the alternator and some running off the timing gears. Maybe I am confusing it with the 2.8.

As for Japan modification, I can say, that some engines have different oil filters (222&226) and some have two 222 filters. Some have EGR system, and some don't.

Thanks. As long as they all bolt in the same way it will save a head ache.