Is the XJ engine the same as the TJ YJ?

Im sure this is a noob question but i did search

Is the engine from the TJ or YJ the same as the 4.0 HO fitted in the cherokee XJ? The reason i wanted to know is that i have seen the Avenger super charger but it says that it is only for the TJ and YJ i wanted to know if this was due to some internel diferances between the two engines or just clerance problems.

If its just clerance = NO PROBLEM i love cutting holes in my xj.

Block itself is the same depending on years, 96-2000 is ported for hp and what not, but the main diff is the external mounting of accessories and brackets. But they do make a supercharger for the XJ 4.0!

TJ here..http://www.naxja.org/forum/showthread.php?p=243720350#post243720350

http://www.naxja.org/forum/showthread.php?p=243819651#post243819651

But link for charger...

http://www.jpmagazine.com/techarticles/engine/154_0703_jeep_power_upgrades/index.html
http://www.jeep4.0performance.4mg.com/forced_induction.html

water pump on a TJ sticks out a little further than the XJ, not sure about any other pulleys. When I took the pump off my buddies spare engine (out of TJ) to replace mine, the pulley or bolts stuck out to far, into the clutch fan.
But as said above, most else was the same, as I saw it.