Swapping a 4.0 TB into a 2.5

[Camshaft]

I posted this in Street Perf. but I got no replies, i figured I might have posted it in the wrong forum, so here goes:

I have a 2000 Cherokee with a 2.5. At my next oil change, I plan on adding a K&N filter, an Airaid throttle body spacer, and a throttle body from a 4.0. Because the 4.0 TB is bigger, should I get the spacer for the 2.5 or for the 4.0? Thanks!

Is this even worth doing? Will I see any gains over the stock TB?

 

[Dr. Dyno]

From what I've heard it's a very good upgrade. Do it, and get the 4.0 spacer as well.

 

[Camshaft]

Thanks! Will do.

 

[Purple]

get a 62mm throttle body, as for the spacer, my 98 started shifting at weird times/rpms with the spacer, i tossed it. Yes, i had these spacers installed
K&N made a world of difference too... It revs quicker, and the response is much more better. It was worth every penny in my opinion.

 

[Camshaft]

Does anyone have a stock one laying around?