my horseys need to gallope
Newbie
Joined: Nov 2010
Posts: 27
Likes: 0
From: Queen Creek, AZ
Year: 1999
Model: Cherokee
Engine: 4.0
So i'm sure i would of found the answer to this question if i had searched a little more but here it is.... So i installed some Autolite Spark Plugs in my 99, I know stupid me i should of got champions, And now i think it might be misfiring but not sure. I gapped them at .035 but she's feeling a little odd at times and am wondering if using the autolites is going to mess with my MPG's, I also installed a new air intake so dont know if that could be part of the problem or be a solution. i'm new at this so cut me some slack. Thanks in advanced for the help

I hope so. The D35s suck for pretty much anything other than street driving.
If you don't have the D35 you've either got the Chrysler 8.25 or a D44. Both are significantly better.
Senior Member
Joined: Jan 2011
Posts: 689
Likes: 2
From: Upstate N.Y
Year: 2000.1999,1996
Model: Cherokee
Engine: 4.0
Gearing is about the most upgrade you can do to a 4.0 without a complete rebuild to a stroker that make's torque Torque is what you need and not horsepower.Of course if you still think it's HP you need (because you have done NO study into it) swap in a V8.

CF Veteran
Joined: Mar 2010
Posts: 6,685
Likes: 6
From: Jacksonville, FL
Year: 92
Model: Cherokee
Engine: 4.0
Originally Posted by 413maxwedge
Gearing is about the most upgrade you can do to a 4.0 without a complete rebuild to a stroker that make's torque Torque is what you need and not horsepower.Of course if you still think it's HP you need (because you have done NO study into it) swap in a V8.<img src="https://www.cherokeeforum.com/attachment.php?attachmentid=41737"/><img src="https://www.cherokeeforum.com/attachment.php?attachmentid=41738"/>
CF Veteran
Joined: Sep 2010
Posts: 4,968
Likes: 0
From: Salt Lake City, UT
Year: 2000
Model: Cherokee
Engine: 4.0L
don't put gears in the D35... at least get a 29 spline 8.25 or a D44 and re-gear it. better to spend the money once. 34 inch tires will kill a D35...
34's would be good with either 4.56's or 4.88's depending on your driving/use. tons of calculators.
also in the second pic where you cleaner the casting you can see a tab that is on the lower right of the diff cover. this will tell you the gearing it has now (unless its been changed)
34's would be good with either 4.56's or 4.88's depending on your driving/use. tons of calculators.
also in the second pic where you cleaner the casting you can see a tab that is on the lower right of the diff cover. this will tell you the gearing it has now (unless its been changed)
CF Veteran
Joined: Aug 2010
Posts: 2,112
Likes: 4
From: Wantage, NJ
Year: 1995
Model: Cherokee
Engine: 4.0 I6
dumb luck, but also going EASY on the skinny pedal will get you much further with any axle. some break d30s with 33s, others have d35s that survive 36s, has a lot to do with driving style



