basically - no, without changing mounts you're stuck replacing with the same
as far as changing engines (I assume you'd want to go for more power) the easiest (but not the cheapest) would be to install a stroker, as it's basically a 4.0 with different internals. but there's no change (that I'm aware of) in motor mounts or wiring.
next easiest (and possibly cheaper than the stroker, depending on your source for engine) would be a carbed small block v8 (Chevy, Ford or Mopar).... for the most part, that's just a matter of changing the mounts, as there's really no wiring to worry about. This option though would make your YJ not "street legal" in most areas due to it wouldn't pass visual inspection for emissions requirements (that's up to you to find out for your specific area)
[FONT="Comic Sans MS"][COLOR="Blue"]Sean B. - Schenectady, NY - 95 YJ, 350/700r4/NP241, JB Shorty SYE, 8.8 rear, 2" BDS, 1" homebrew shackles, Daystar 1" BL, TJ flares, 35x12.50 General Grabber AT2 on 15x10 Bart D-Truckers, Polyshield polycarbonate windshield, HD over/under crossover steering
[/COLOR] [COLOR="Red"]swap/build thread: [url]http://www.jeepforum.com/forum/f22/after-almost-4-years-finally-my-own-build-swap-thread-1542284/[/url][/COLOR][/FONT]