Sanden's are also on XJ's, I have one.

Did not know that,Which model Sandens? Well with that being said there is alot of good info on converting Sandens on www.mazdabscene.com

here's a write up on a wrangler- close enough.
http://jeep.off-road.com/jeep/articl....jsp?id=260374

here's the one I saw a while ago for an xj!
http://www.jeepforum.com/forum/showthread.php?t=471962

also, whether you have a tank in your setup or not, you need to have a pressure relief valve, so nothing goes boom.

Here is what I am copying this
http://www.jeepforum.com/forum/showthread.php?t=471962 using the stock compressor on my 1990 xj so far it has cost me $70 which i did not expect, but I bought stuff I may no have needed and already have stuff I need.

I did mine for less than $100, that includes a junkyard A/c. i need to get pics of it, but right now I have it filling a 5 gal tank[I changed out the fitting on the tank to accommodate air hose instead of that cheesey air chuck] with 140psi[110 on and 140 off pressure switch] and it does that fairly quickly. I used it as my primary air compressor when I was at a friends house stripping a blazer for parts. It did a pretty good job keeping up with the impact gun.

Mine is a Sanden SD208. It is a 5 piston compressor capable of 9cfm and up to 300psi.

If I recall the 708 is the most converted one I've seen, I know my Jeep has a 508

Hey, theres a great write up in the april issue of JP.