Bored throttle body is probably your most noticeable difference for the money.
Everyone seems to have differing opinions on the tb spacer - I say don't get one unless you are going to have it bored the same as your tb.

 

I've found that a good header and full exhaust replacement is good way to start. Three-inch exhaust is overkill for the 4.0. 2.5" will work just fine. A cold air intake and a bored throttle body will also help with horsepower and supposedly gas mileage. The throttle body spacer won't do anything. Camshaft and valve spring upgrades always make a difference.

Start out with the easy stuff and work your way up. Forced induction and engine swaps are time consuming, costly, and a major pain in the ***. Work with what you've got at first and then decide later if you want to get hard core about it.

 

I put a k&n filter on and a Magnaflow highflow cat with a Flowmaster Super 40 and went 2 1/2" pipe from header back including the cat, not only does it sound sick but i honestly got a power increase and .8 mpg increase on my last tank and that was with getting on it a bunch to show off alittle bit also. I got 284 miles on my last tank before my light came to refill. Im not sold on all the little things these companies say there product will do but I really noticed a diffrence with the exhaust upgrade and I'm sure the fresh cat itself helped.

 

drop in a 350... :-)

 

A small block chevy is the way to go. If you add the width of the intake and exhaust manifolds on the stock 6 Cyl., the small block chev. is actually smaller width and length wise. Instant horse power.

 

ACtually, I was kidding just a little-- sb chevy is a huge undertaking... If I was going to do it all over again, I'd seriously consider stroking the 4.0-- you'll get very similar hp numbers, and it probably will end up costing you less... there used to be an outfit that sold crate motors that were stroked for something likie 5 grand that were direct drop-ins. if you're really serious about power, I thing its something worth considering.

 

You're talking about:

Titan Engines in Florida http://www.titanengines.com/

HESCO in Alabama http://www.hesco.us/

or there is another one I know of but I can't think of their name...

 

You'll be hardpressed to get Beastly performance out of a stock 4.0L without spending copious amounts of money on internals, machining, bolt-on's etc.

Take a look at the insane inline JPMag built. Sure its posible to get huge HP and Torque numbers from a 4.0L, but who here has deep enough pockets to do so?

Skip the stroker, the performance gains aren't worth the dollars spent.
SB Chevy is fine if you add some aftermarket goodies to it.
Vortec engines are lighter and produce more power in stock form than a traditional SBC.

 

Put mustang injectors in your fuel rail. A 2.5in exhaust. Header cold air intake. are ways to start. You can always do a cam and head to it.

 

http://www.jpmagazine.com/techarticl...rbo/index.html

 

methanol @118 octane and nitromethane blend added with 15% of MTBE, and you will be the god of beasts in your cherokee for 15 minutes...

 

Im meaning no sort of disrepect but why would you take a jeep w/ a reliable inline 6 cyl. out and ruin it by replacing it with a POS GM V8 . My 4.7 stroker will dust down 350's all day and as far as pulling torque , it does just as good as a V8 but uses alot less fuel . You want a " MEAN " jeep call Titan Engine's in Florida !

 

I've ben down that road and wasted thousands on a stroker without getting the BHP that people say they get. Never again.

My POS GM 5.3L Vortec puts out 285HP in pure stock form. I'm above that just by installeing a set of headers. So far I'm at about $2k (+/- a few hundred) and I'm just waiting on some spare cash to get my gauges.

So how much HP are you making and what did it cost you? Got any Dyno data from your rig to support your comments?

 

Why you gotta be a hater?
Small blocks have been around since 1952. SAying that "my 4.7 stoker will dust down 350's all day" is, to be blunt, an innane comment.
Was the 350 you were "dusting" a late model lS2/ls1/ls6? an lt1? Jeeze, I've seen an LT5 in a cherokee-- you dusting that?
Crap, unless the stroker was done really well (I've seen tons of POS strokers out there), I highly doubt you're even near the hp/tq of my l98-- much less "dusting" it. now, if its a targetmaster junk-box crate motor (which there are far to many out there, imho), then I may agree with you. .... get what I'm saying?

Aned as for reliability, I probably would have agreed with you before I did my swap-- I would have predicted that a 350 swap would be unreliable. But have to admit, with 600 miles on the block, the thing is as reliable as clockwork--- tap the key, it starts, and runs all day long.

As for fuel milage, this again, is an overrgeneralization. A 4.0l gets an estimated 17/20 MPH. And thats high, in my opinion. In the first 500 miles of mixed use with my 350, I'm getting about 14 MPH-- and I haven't been too easy on the go-pedal.

Why? Becuase the 4.0l, while it is a great motor, has to work harder to put out the same power that the SB chevy does.

Note that I'm not knocking the 4.0l-- I used it happily for years-- or the stroker kit (see my last post, where I actually suggested a stroker over the 350). But if you're going to talk crap, know your facts.

 

Actually the 265 cu. in. Chevy V8, Grandfather to the current small block, came out in '55, but I'm not a Chevy guy.
Dan