'88 I-6 block into a '92?

I have a 4.0 I-6 engine from my wrecked '88 XJ. I replaced the '88 with a '92 XJ having a 4.0 I-6 High Output. But the '92 is now getting a little tired.

It would be really nice to rebuild the '88 block at my leisure (like a short block rebuild), then swap it in. I know that I'll have to use the head from the '92.

My question is: will the '88 block replace the '92 block?

And another question: blocks from different years are supposed better or worse depending on the year. They are serialized somehow. Where do I look for the serial number and what's good?

Thanks!

The date is stamped by the distributor.

There is no dimentional differences between blocks from 87 to 95.

In 96' they went to a main cap girdle for strength, and to reduce harshness/vibration/noise.

Even with the main cap girdle difference, all the blocks are swappable back and forth.

I thought I had heard somthing about earlier blocks using a higher nickel content (= stronger), but don't know if that's ever been proven, or when it was supposed to have stopped.

As a short block it'll work fine. Aside from the head, I trust you know that you have to use the flywheel/flexplate from the 92 because the 88 uses a different system.

Thanks for the info! So now I can rebuild my '88... but I have another question for which I'll do a new post.