Well technically I don't think the 258 made it into the Gladiator, because they changed the name from Gladiator to J-Series in 71. I think the only six at that time was the OHC 230 Tornado, but the 232, and the Buick V6 might have been offered. the J-Series will have the 258 for sure. I didn't mean that to be a smart *** response. I just didn't want to say yes, and then you look it up, and find out otherwise. The Gladiator, and J trucks are the same thing with slight differences.

If the 4.0 feels weak it's because somethings wrong, or it's not geared right. My 87 Cherokee had 3.08 gears got 23 MPG, and still ran like a raped ape.

 

Is it running larger than stock tires? I've got close to factory size on mine (235/75/R15s, factory size is 215/75/R15...very little difference), and it will get up and go in any gear. It has the 4 speed auto.

 

Just watched trucks this morning,they had a jeep with a stroked engine 4.0 to 4.6.was really impressed with the dyno results.even with the driveline loss on the chassis dyno, and don't think it would make over 150 hp at they crank.IMO

 

yeah, i watched it too

 

If I remember correctly from when I worked in the wrecking yard, the 4.0 got fuel injection when Chrysler took over in '87, which helped power some. Then in '91 they revised the intake and head design to come up with the 4.0 "HO". But there wasnt very much "HO" since it only made 15 more horsepower.

 

He has 33's but even with 31's it was doggy!

 

1987 was the first year for the 4.0, it came out with EFI, and it was in the Cherokee only, they decided to put it in the Wrangler in 1991.

 

4.9 is bigger than 4.0. its not really a fair comparison. of course a 4.9 will do anything better than a 4.0 at the same rpm and and stock fuel systems.

 

you guys think in litres....i think in cubic inches. how would a 240 compare to a 258? or a chevy 250?

 

how does a 300 compare to a 292, chevy?

 

I owned an 89 Cherokee with EFI 4.0. Worst engine I've ever owned...it was a dog, couldn't keep it tuned, and the manifolds cracked by 71K miles. I wouldn't put that engine on a lawn mower.

 

Actually the 4.0 is 248 c.i. As a former Jeep owner (w/ a 4.0) I know for a certainty that the 300 will not take off as fast, nor hold a high speed like the Jeep engine, HOWEVER, when it comes to towing, the Ford 300 is a MUCH better engine due to it's low-range torque. The 4.0 Jeep engine came with only about 120 lb ft of torque where-as the 300 Ford has about 150-175 depending on which model of vehicle you bought.

 

The Jeep Comanche could be purchased in 1988 with a 4.0. I had an '88 Comanche with a factory installed 4.0 fuel injected engine. AWESOME ENGINE! If not for running it 6 years with a knock which finally lead to it's demise, the truck would still be in my possession. I have since gotten a 1984 Ford F-150 with a 300 c.i. I-6 which has more pulling power than the Jeep ever dreamed of.

 

The 300 paired with a 4 speed or 5 speed can be a easy opponent in a race. as for pulling and or off- roading gimme the 300 anyday my jeep had a 4,0 in it and it was alright never got stuck. did really good in the snow but id rather has a 4.9L 300 INLINE SIX

 

Yeah the 4.0 was also in the Commanche, but it's pretty much the same thing as the Cherokee, and I didn't think anyone would mention it.

The 4.0 is a 242 cubic inch engine, and they usually go 300k miles or more. The Jeep six is a screamer for sure. AMC, and later Chrystler actually put a really good flowing head on it, unlike Ford who nutered their 300 six with a head that sucks.

Like I said before the 4.0 Jeep is great for a lighter to mid weight vehicle, and has good HP, and good TQ for it's size, and the time. The 300 has been in dump trucks, but it has terrible HP, but good TQ for it's size, and the time it was used. I would like to see what a 300 could do with a head that flows like an aftermarket aluminum head made for a 302 or something.