I've a 87 4.2 with AC. The engine was rebuilt so I can't assure you that it was the factory set up. The belt numbers did not match up so I had to go with what was close. The Alternator belt, I had to get from a lawnmower supply believe it or not.
There are a lot of little things that have lead me to believe that this was a very early 87 YJ with lots of CJ parts.

Good luck

 

Thank you very much, JDC. I see some minor differences, but all of the major component placements look the same. Very helpful. Thanks again.
Russ

 

I just did this with a 100% stock '89 YJ with the 258 and A/C. I'll be glad to take a pic of the belts I bought

another thread on this
belt routing for a 89 yj 4.2 - JeepForum.com

 

Thanks for all of the input. Got it all figured out now, so here's some info:
For my '87 YJ, this is the belt routing and NAPA #'s for the belts:
If you have all three V-belts off, they need to go on in this order:
1) First belt goes around pulleys for P/S pump, crank, and water pump. NAPA #9465
2) Second belt goes around pulleys for crank, water pump, and A/C compressor. NAPA #7475
3) Third belt goes around pulleys for the alternator and A/C compressor. NAPA #9245
Thanks again,
Russ