The throttle bodys are the same dimentions. The manifold opens wider under the throttle body so you don't need to change the manifold at all. The intake snorkle could be left the same or a high flow kit could be installed for a 2.5 or 4.0. The 4.0 kit may be a little over kill cause the stock 2.5 will never draw as large a volume of air as the 4.0. OR swap on the 4.0 stock air intake. Try as I may, there is only so much one can do to bump up the HP of a stock 2.5.
While I usually dont troll where I dont know squat...you are in the correct ballpark-
the engine can only draw so much, and exhale so much(without supercharger/turbo help). What we do, is provide more "room" for both, to make more power, within those limits.
If you provide more available air/fuel, you should provide more exhaust ability- manys a time Ive seen people do all the special intake mods, and not even think about their exhaust..then complain because the performance gain wasent "astounding"!..more like..."just a bit `o difference".
For every reaction, there is a reaction- more fuel, more air, more exhaust-- kill one, diminish the others.
I`ll use my old 89XJ I had as a perfect example-- I did one of the first cold air induction/homemade intakes, and had access to a bored out throttlebody(which promptly screwed with my 02sensor-nother story/nother time)- I regapped the plugs, hooked everything up(replaced the 02 sensor) and whammo...power!...not much, but there....
Moved to the exhaust, completely emptied the cat, and put a downspout exhaust about midcab. MUCH more power....in the TOP end. Nice bit of power in the midrange, lost the low end(killed an 02 sensor). Ended up replaceing the cat with a (then) high flow version-ran new pipe from it out the back...Lost the high end, gained all kinds of power in the midrange...low range was a tire burner(killed another 02 sensor).
Pulled out the "experimental cat"(drillbit- 1inch- halfcat,half hole) reinstalled, BUT, put a restrictor on the end of the muffler-believe it was halfsize, but its been awhile.
power everywhere....good high end, midrange, decent lowend pull. I removed the restrictor, and felt less low end...I had reached "the point".
I provided ample intake, and "tuned" the exhaust for backpressure/lack of.
A freeflow exhaust wont work, and too mush backpressure will tarnish the highend...
Then I installed a cutout......and fried a few more 02s.
I miss that jeep.
The 2.5 isnt inherintly a bad engine, its just being asked to do something it shouldnt, and it does that well enough. It can feasabily be boosted up to higher horsepower and torque, but within limits...and those limits are somewhat small. Any increase on the 2.5 is something to talk about.