Amazon has Mopar parts at decent prices. At RockAuto.com you can do a search for the part number and Mopar brand for Mopar parts that won't show up in a regular Year/model/engine search.

As far as body parts and the such - there are no retail/dealership options - you will have to hit the Junkyard, or scour the eBay/Craigslist listings for original parts.

 

www.teamcherokee.com has a good selection of replacement parts. I've used Morris 4x4 a few times but their prices aren't the lowest. I've actually had good luck with my local dealer for a lot of parts and their prices are reasonable and I don't have to pay shipping.

 

First thing you need to do is go here:

https://xjjeeps.com/

Don't just download the parts catalog for your Jeep. Download all of them. Having the part number will then let you do a Google search.
Example:
This is the part number for a gas tank skid plate out of my '88 to '90 parts catalog.
5200 1512.
Notice the space between the first 4 numbers and the second set of 4 numbers. Get rid of it so it reads like this. 52001512. Don't ask me why cause I don't know. It makes a difference when you Google it. Try it and you will see what I mean.
Now sometimes doing that won't yield any results. Sometimes putting the word Mopar in front of the part number helps. Sometimes you have to get a little creative when searching.

Now the reason I told you to download all the parts catalogs. Many parts will fit a variety of years. Some won't. This is for boneyard searches. If a part is not year specific you will know what year XJ's you can possible get this part from. So the boneyard does not have a '90 but has a '96. Maybe it matters. Maybe it doesn't. Also when you google a part number if a Mopar online parts place comes up they have a "What This Fits" tab. Sometimes depending on the part it was used in a variety of Mopar vehicles. I mean other vehicles besides Jeeps. So when you are hunting for parts in the boneyard you can look at other vehicles to hopefully find what you need.
Example. This is the gas cap for my '00 XJ. Click on the "What This Fits" tab.

https://www.factorychryslerparts.com...2030377AB.html

See all the vehicles this fits. Now this does not happen often but does from time to time.

Napa is also good for this. You can cross a factory part number on their site. Here is my gas cap again.

https://www.napaonline.com/en/p/BK_7031716

Click on the words "Buyers Guide" down lower on the page and you will see all the vehicles that this part will fit just like at the link above.

When Googling you might find NOS, New Old Stock, on Ebay. Might find the part from Mopar online retailers. Might find aftermarket versions made by companies like Crown, Omix-ADA, etc.
Also don't just assume that your local Jeep dealership does not have this part, because it is for a 30 year old vehicle, or can't get it. Also just don't assume that they won't be competitive pricewise. As a matter of fact might not be a bad idea to try and build a relationship with the guys there. My guys at my local dealership are great. I am pretty good at finding parts and part numbers. But sometimes the parts catalogs can get a little confusing. They put up with me and answer all my stupid questions.

Last sometimes when you Google a part you will find an actual Mopar online retailer that says they have the part. You order it, pay for it, and they whack your card. Then you get an email saying that they don't. And it takes forever to get the money back on your card. It happens. Just cause it is on the internet does not mean that it is true.

 

 

There is one thing I forget to add. Hardware. Nuts, bolts, screws, etc. Many times in the parts catalogs they will not only tell you the part number for the hardware but also tell you what the length, thread pitch, etc is. This helps when replacing hardware. It might not be a perfect match to the factory one. Ever see how some bolts or nuts kind of have a built in washer.




Much of the factory stuff is like that. Frankly you can just buy a regular bolt and use a washer. There has been a time or two when you need factory hardware. But much of it can be replaced. Just make sure the Grade is correct for the use and that it is close enough in length. I invested in one of these for when I have resuse factory hardware.

http://www.tooldiscounter.com/ItemDi...?lookup=KAS971