91' Jeep YJ Wrangler - Off Road Magazine

Our two-month project took 11 months but is finally just about finished. Like all projects, especially backyard projects, things took a little longer than expected with daily schedules getting in the way.

In case you're just joining us, Project Old School is a '91 Jeep YJ Wrangler we built retaining its "old-school" leaf-spring-under-axle suspension. The Jeep was built in the backyard and garage of our neighbor, Eric Maughan, just as they used to be in the "old" days. We installed a new 5.7 MPI Hemi crate engine from Mopar Performance, Advance Adapters' 727 TorqueFlite automatic transmission and Atlas transfer case, Tom Wood's driveshafts, Currie Iron Jock 60 front and rearends, Currie front and rear bumpers, Deaver supple leaf springs, 36-inch Interco Irok tires on Mickey Thompson Classic II wheels with OMF beadlocks, a gas tank from Gen-Right, Master Power brakes, PSC power steering with hydraulic assist, Ford Grabber Blue paint by Elden Dattage Towing & Auto Repair, and more parts than we can count from 4 Wheel Drive Hardware that made our Project Old School YJ better than it was new.

Even with the Hemi, we wondered whether we would have enough power off-idle to spin the 36-inch Iroks that actually measure larger than most 37-inch tires and as large as some 38s. The 727 TorqueFlite has a 2.45 First gear, and we had only put 5.13 gears in the diffs. Our worries were unfounded. With the 1,800-rpm stall-speed torque converter, we can spin the big tires at will and, in fact, have to modulate the brakes a bit when trying to finesse at crawling speeds in the dirt. The Hemi provides instant throttle response and gobs of torque right off idle.

The rest of the YJ works as we hoped. The Deaver springs are soft and allow plenty of articulation, the Master Power power brakes afford plenty of stopping power, and the PSC ram-assist power steering allows us to use one finger to steer, even in the rocks. The Advance Adapters aluminum radiator and fan combo keeps the Hemi cool even on the hottest desert summer days. The Wrangler is even better than we thought it would be when we started this project.

4 Wheel Drive Hardware was our one-stop shop for parts to make our tired Jeep new again. Weatherstripping, a heater motor, interior pieces, seats, even front fenders and a windshield frame were a phone call away and made our restoration go smoothly. The only thing that didn't go smoothly was trying to figure out what torque converter, flexplate, and starter to use (see "Project Old School," part two, July '07). Now that we know what works, that's not a problem anymore and yes, we would DEFINITELY use the 5.7 MPI Hemi crate engine in another project. Project Old School is an unqualified success!

The crossmember/skidplate is completely flat under the YJ.
The O-R Fab sport cage was painted to match the Jeep.
A strong and fast Warn 9.5xp winch sits above the Currie front bumper.

The painted body was easily lifted onto the rolling chassis. Norm looks on, supervising the installation.
The painted body was easily lifted onto the rolling chassis. Norm looks on, supervising t
Old School's frame was sound but looked bad, so off to the body shop it went.
4 Wheel Drive Hardware sport seats are extremely comfortable for the long haul. They bolt right on the Jeep seat brackets and recline.
4 Wheel Drive Hardware sport seats are extremely comfortable for the long haul. They bolt

The body shop did a great job making the place look stock where we had pushed up the floor to clear the clocked Atlas T-case.
The body shop did a great job making the place look stock where we had pushed up the floor
A strong and fast Warn 9.5xp winch sits above the Currie front bumper.
Here's the frame after we got it back and bolted in the drivetrain. Our Atlas transfer case runs a 3.8:1 Low range. The Gen Right stainless gas tank is a flawless piece of work.
Here's the frame after we got it back and bolted in the drivetrain. Our Atlas transfer ca

37x13.50-16 Interco Irok bias-ply tires are mounted on 16x10 Mickey Thompson Classic II wheels with OMF beadlocks. You can see that we decided to use hub flanges instead of locking hubs.
37x13.50-16 Interco Irok bias-ply tires are mounted on 16x10 Mickey Thompson Classic II wh
It was a bit tedious to reinstall the dash, but it was worth it to make sure everything was new or worked. Here's what it looked like as we were getting started. The high-quality Lokar shifter looks and works great.
It was a bit tedious to reinstall the dash, but it was worth it to make sure everything wa
The body shop did a great job making the place look stock where we had pushed up the floor to clear the clocked Atlas T-case.
The body shop did a great job making the place look stock where we had pushed up the floor

And here's the nearly finished product. We still have to install the head unit with Sirius satellite radio. The leather steering wheel's from 4 Wheel Drive Hardware. A Tuffy Security glovebox keeps small items secure in the open Jeep.
And here's the nearly finished product. We still have to install the head unit with Siriu
The body had some flash rust and a few small dents, but was surprisingly sound once the crew at Elden Dattage Towing & Auto Repair got under the paint. The windshield frame is from 4 Wheel Drive Hardware and replaced the stock one that had rusted through in places.
The body had some flash rust and a few small dents, but was surprisingly sound once the cr
The PSC steering gearbox is very strong and reliable. Here, we haven't plumbed the system yet, as you can see.
The PSC steering gearbox is very strong and reliable. Here, we haven't plumbed the system

We can't say enough positive things about Advance Adapter's new line of aluminum radiators with Spal fans. Don't confuse these radiators with others that look similar and don't work. Our Hemi runs cool in the hottest temperatures. We installed one of these radiator and fan combos on another truck we had that was always overheating. No more problem!
We can't say enough positive things about Advance Adapter's new line of aluminum radiators
As always, the PSC power-steering system with ram assist works perfectly. We opted to go with PSC's 1.75-inch ram that isn't quite as powerful as their larger rams are. The smaller ram works great in this application. You can also see the tie rod and drag-link rod ends from HM Engineering. It pays to go with better, quality parts from the start rather than replace cheap garbage later with the better pieces. The front and rear Currie Iron Jocks carry 5.13 gears and Detroit Lockers. The Deaver leaf packs are supple and allow plenty of articulation.
As always, the PSC power-steering system with ram assist works perfectly. We opted to go
The 5.7 MPI Hemi crate engine from Mopar Performance is a great mill for projects. With a stand alone computer, it installed easily into our Jeep. The Master Power brake booster and master cylinder provide plenty of power to the Wilwood and Currie disc brakes. The Optima YellowTop sealed gas recombinant battery can be mounted in any position and doesn't leak.
The 5.7 MPI Hemi crate engine from Mopar Performance is a great mill for projects. With a