Dana 35 Axle Upgrades
Question: I have a '98 Jeep Cherokee 4.0L with a Model 35 rearend. I need to rebuild it, but I'd like to upgrade it to allow a 4.5-inch suspension lift and 32-inch tires. My plans are to make this vehicle a daily driver that can go "play" on the weekends. Do you have any suggestions?
Answer: I assume that you mean to rebuild the whole Jeep, not just the rearend. First off, don't even think about rebuilding the Dana 35. It is a notoriously bad axle to run with any tire size larger than stock. If you break an axleshaft, which you will in time, the remaining portion of the axleshaft, along with the wheel, will part company with the Jeep and leave you most likely stranded.
A couple of companies such as Alloy USA and Superior Axle & Gear sell a larger-diameter 30-spline high-strength axleshaft. However, it must be used with a special aftermarket locking differential such as sold by Detroit Locker. Last time I checked, the price was about $1,100, not including labor. OK, you gain axleshaft strength and a locker as well, but the axlehousing is a bit on the weak side, and I have seen several of them bend quite badly. I believe that someone does make a truss for it, but that is even more money.
I really think that the best bet is to swap it out for a Ford Explorer rear axle. They come with the larger-diameter axleshafts, a much larger ring-and-pinion gearset, and in either a 3.73:1 or 4.10:1 ratio. We made this swap in our "Project Ain't it Grand-er," which you can find on fourwheeler.com (under "project vehicles"), and while we had to convert the Ford rearend to coil springs, you would just have to relocate the spring pads as the Explorer uses leaf springs.
Now I question the fact that you say your '98 has a Dana 35 rear axle. I was under the impression that the '96-and-up Cherokees used what is referred to as the Chrysler 8.25 rearend with 29-spline axleshafts. It's easy to tell the difference between the two, as the rear Dana has a cover that looks similar to the cover on the front of your Jeep, while the Chrysler rearend cover is almost round and has a smooth face. This is a fairly decent rearend and should hold up well to a 32-inch tire.
If you do indeed have a 35 rearend, then another choice would be this Chrysler rearend, and it would be no harder to install than bolting it in place. Keep in mind that the '91-'95 Cherokees also used this Chrysler rearend but with a small axle spline count of 27 splines, which is not much better than the Dana 35.
You might also want to consider a Dana 44 out of a TJ, but this means that the coil-spring mounting brackets and such would have to be cut off and spring pads welded on. Whatever your final choice is, just be sure that the front and rear axle gear ratios match.
Now as to a complete rebuild of the Cherokee, the starting point can be anywhere you want it to be. There is a plethora of great suspension systems, tires, wheels, bumpers, and engine performance parts available for the Cherokee, a lot of which are advertised within the pages of this magazine. Have fun.
Building A Dodge 318 For Boggin'
Question: I have a question for any of you old Dodge guys out there. I have an '83 Dodge Ramcharger (Prospector edition) that I have been using in the local mud races. I need to know if I should ditch the two-barrel intake and carb for a four-barrel instead. I'm running a 318 small-block with a set of Hooker headers. The engine has a lot of power and response, but recently I swapped my set of Super Sport 31x10.50/R15s for a set of Mud King 35x12.50R15s. I'm running 3.21:1 gears (stock ratio) and wonder if the four-barrel will give my old Dodge a little more torque.
This Ramcharger is also my weekend play toy, and I really don't want to make it into a full racer. I'm just trying to make an all-around good wheeler.
Answer: I doubt that you are going to see much torque increase with the carb/manifold swap-at least, not enough to make the swap worthwhile at this time. What you really need to do is get rid of those 3.21:1 gears and get down in the 4.56:1 ratio. If your primary use is for mud racing, then an even lower gear may be better. The swap to the 35-inch tires killed your overall gear ratio, making it equal to having about a 2.90:1 ratio. The lower gearing will put the rpm into a range where your engine will be making better horsepower and torque a lot quicker when making you run down the track.
When the gearing has been changed, then you should consider making the carb/manifold swap along with headers and a low-restriction exhaust system. One of the mistakes people make when doing a carb/manifold swap is to think that bigger is better. This is generally not so unless you have a full-out racing engine. Keep the carb in the 600-cfm range, and make sure you buy a manifold that matches the rpm range of the engine. You might want to consider one of Edelbrock's Performer packages that include a camshaft change as a starting point.