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1989 Chevy Blazer - 14-Day Blazer: Part 1

Posted in Features on October 27, 2014
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Longtime readers may remember the tired old orange ’72 Blazer that took part in the very first Ultimate Adventure way back in 1999. That Blazer happened to be mine, and I beat the snot out of it during the trip, wheeling it on well-known trails from Arizona to Colorado. Even though I committed the cardinal sin of trailering it on all but two driving legs of the trip (there wasn’t a no-trailer rule back then), that Blazer did pretty well despite several Dana 44 front axleshaft swaps thanks to the 36-inch Super Swampers it was running (chromoly shafts were pretty much unobtanium in those days).

I’ve been fortunate to take part in many Ultimate Adventures since then, but since the first UA I’ve ‘wheeled mostly Jeeps on these epic trips. That old Blazer . . . well, it suffered further abuses, got parked, and eventually found a new home. I’ve always missed my first Blazer, then a chance encounter with a Craigslist ad had me thinking about getting back into a fullsize rig. With UA coming and General Péwé always wanting vehicles that aren’t Jeeps on the trip (there are always plenty of seven-slot grilles), I contacted the seller, and the next thing you know I was the proud new owner of a vehicle I didn’t need but really wanted.

A crony isn’t much help without a reliable rig, so making the Blazer reliable was job one

The ’89 Blazer I drove home with, title in hand, six weeks prior to the Ultimate Adventure was perfect in just about every way. The previous owner had focused mostly on reliability and had obviously 4-wheeled it judging by the battle scars. This meant I didn’t have to feel bad about wrinkling it even more. The TBI 350ci engine ran like a top, the 700-R4 tranny and NP208 transfer case were reportedly fresh and shifted perfectly, and it was obviously an Arizona vehicle with no rust and the sun-bleached paint to match. The real scores were the Dana 60 front and 14-bolt rear, which are reliable as a hammer and just as strong. With a full rollcage, rock sliders, 37-inch-tall tires, and sheetmetal trimmed in all the right places, it was a pretty good score for the asking price. But as with any vehicle, there were plenty of warts to go with the benefits. Like most people, life and a regular job kept me from really doing anything other than planning the build and getting parts on order until just two weeks before I had to be at the start of the event 1,100 miles away from my house this year. Other than a quick 300-mile overnight trip the day after I bought the truck to test how reliable the engine and transmission were, I didn’t touch anything. What could possibly go wrong?

The purpose of having the old cronies on the UA is to support the trip and basically handle anything General Péwé needs, whether it’s extracting a rolled vehicle, finding a lost member of the group, fixing a broken rig, going on a parts run, or finding him a cold Corona at camp. A crony isn’t much help without a reliable rig, so making sure the Blazer was reliable was job number one. Job number two was making sure the rig met the requirements for the event. Third was focusing on things that might actually enhance its trail performance. Follow along as we cover the first of a two-part series on throwing a secondhand Blazer together in just 14 days and attempt to make it survive UA 2014.

Here’s the score as we purchased it: a ’89 Blazer powered by a tired TBI 350, 700-R4 tranny, NP208 transfer case, Dana 60 front, 14-bolt rear, 6-inch lift, and 37-inch tires on Hummer military beadlocks. The purchase price was pretty low, but there were plenty of surprises in store. Despite the owner’s recommendations, we immediately drove it on a 320-mile round-trip journey into the mountains and crashed the Overland Expo. We tried to fit in with all the khaki outfits and rooftop tents as best we could. It didn’t work. But the Blazer was flawless on and off the pavement, which was the important part.

We’re all about character, and this Blazer has plenty of it, including a bullet hole in the windshield. The previous owner was evasive as to the circumstances surrounding it except to say that it was parked and he wasn’t anywhere near it at the time. We didn’t dig any deeper, but the extensive spiderweb cracks had us concerned about attracting unwanted attention from authorities during the trip, so we added new glass to the parts list.

Underhood we were happy to find a rock-solid reliable small-block Chevy with equally simple and reliable throttle body injection. Other than some blue smoke on startup and heavy acceleration, the engine and the rest of the drivetrain run and work better than we could have possibly imagined. This SBC era is well-known for valve seal issues, so we firmly believe we should get at least another 100k out of the engine without touching it. Applying the KISS principle, we might address the leaky exhaust gaskets on the unfortunate long-tube headers, but other than some preventative maintenance we’re not going to mess with a good thing.

We noticed that the rear shackle bushings were destroyed before we purchased the Blazer but knew it was an easy fix. We also blamed the bushings on all the popping, creaking, and groaning coming from the rear suspension during the shakedown run. We ordered what we thought were the right ones, but it wasn’t until we blew the rear suspension apart during a rare weekend at home that we discovered that most ’73-’91 Chevy shackles come with 11⁄2-inch bushings, but ours is equipped with relatively uncommon 13⁄8-inch shackle bushings. This would become the start of a theme with this build. Best of all, the rear suspension’s popping and groaning continued once the bushings were replaced.

One of the things we thought about long and hard was the transfer case. The Blazer has a freshly rebuilt NP208, which is plenty strong for most applications but is also plagued with a crack-prone aluminum case and a slip-yoke rear output shaft. It’s actually the predecessor to NP231s and NP241s, which are well regarded and strong. Swapping in an NP205 was tempting, but we didn’t want to lose the 2.6:1 Low-Range of the 208 , nor did we want to go through the time and expense of a doubler (though that would have been a wise choice). We reluctantly chose to stick with what was there because it was working. Time will tell if this was a wise choice.

The Blazer was equipped with 4.10 gears, an open rear differential, and an unknown locked front diff. Knowing that 4.10s wouldn’t be nearly enough to turn 37s off-road, especially in low range on hard trails, we went deep on the gearing with a set of 5.13s from Nitro Gear & Axle. We also opted to upgrade failure-prone 30-spline front Chevy outer stub shafts with Nitro’s chromoly 35-spline shafts with drive flanges. The Ultimate Adventure also requires lockers, and we’ve never been let down by the bulletproof simplicity of Eaton’s Detroit Lockers, so they got the nod for the differentials. Even with these gears we’re hovering around a 40:1 crawl ratio, which is definitely the lower end of ideal for the UA, yet doable. The overdrive of the 700-R4 will save us on road days.

With time ticking away at an alarming rate, we turned to the experts at 4Wheelers Supply in Phoenix to perform the gear swap. They left us in the capable hands Joe Wesolowski, or Old Joe, or just Joe. He has worked at this same shop for 50 years and mostly handles their transmission and transfer case rebuilds these days. He is the authority in Phoenix on all matters of drivetrain, and one of the few who can tear apart a modern 6-speed manual tranny without batting an eye. Joe had the axles torn down in record time. Trivia: Joe taught a young Rick Péwé back when Rick was sweeping floors at 4Wheelers (and he schooled us on a thing or two as well).

GM 14-bolts use a two-piece carrier, and installing a Detroit Locker is as easy as removing the stock side and spider gears and replacing them with the Eaton unit. Note that the stock thrust washers for the side gears are not reused. After cleaning everything up, Joe dropped the Detroit pieces into the carrier and assembled the rest of the carrier. Leave the all-thread and wing nut holding the Detroit assembly together until the carrier is assembled, as this makes like a whole lot easier. Also note the carrier break on 14-bolts is 4.10-down and 3.73-up. This is important when ordering the correct gears for your application.

We’ve covered gear installs step-by-step many times in these pages, so we’ll just hit the highlights. After a thorough cleaning and installing the new bearings from the Nitro master overhaul kit, Joe did the initial setup using the same shims as the original setup, and the pattern turned out to be perfect. We attribute this to Joe’s expertise and the quality of the Nitro gears. With a good pattern the rearend was buttoned back up and Joe moved to the front axle.

The Blazer’s front locker turned out to be a welded open differential, and actually it looked like it was pretty well done. If we were using a transfer case with a 2-Low function, we would have been tempted to keep it. We went with the Detroit Locker instead, but turning will still take some thought on the trail. As with the rear, Joe used the same shims as the front for trial setup, which required pulling the carrier bearings from the Lincoln locker to measure.

The saying goes that age and experience trumps youth and enthusiasm every time, and we believe it. Joe got a perfect pattern on the first shot using the original shim setup, a testament to the quality gears, quality Detroit Locker carrier, and Joe’s attention to detail. We’re sure we would not have been so lucky.

Our original plan was to reuse the inner front axleshafts, but at the last minute we decided having a complete set of spares would be better in the unlikely event we break a front axle during Ultimate Adventure. We obtained some replacement 35-spline inners from Nitro to match the 35-spline outers and joined the two with new forged Spicer axle joints. This combination should be plenty strong for our planned tire size and worn out 350ci small-block.

The last piece of the puzzle is joining the new 35-spline outers to the wheel hubs. We decided to try a set of Nitro’s 35-spline drive slugs, which eliminate the weak link that typical locking hub assemblies create. The tradeoff is that the front axleshafts and driveshaft spin all the time on the pavement, but drive slugs are pretty much bulletproof off-road. We like bulletproof, and since new driveshafts will be part of the mix, we decided to give them a shot. They include a retainer that keeps the cap in place should you want to remove the drive slugs for long pavement stretches.

With the gearing and lockers out of the way, we turned to addressing other needs. We really like the front and rear bumpers the previous owner fabricated, but unfortunately neither one had any sort of recovery point. For the rear, we scored a used trailer hitch on Craigslist for $35. There were some spacers and hardware missing, but we managed to get it mounted solidly to the frame. It hangs lower than we’d like, but it’s a solid rear recovery point that should also help protect the gas tank and the bumper itself, which is made of thinner material than we would like.

There was no saving the front bumper, which was well designed but offered no winch mount nor recovery points. We turned to the full-size Chevy experts at Offroad Design for the ultimate solution: a low-profile tubular bumper with an integrated winch mount and heavy-duty tow points. The bumper ships raw and if we had more time we would have had it powdercoated. Instead we opted to fog it in satin black, which makes for easier touchups anyway. Not only does it look awesome, but it is superstrong and every weld is textbook perfect. It also fit like a glove on our 25-year-old frame. Five Grade 8 bolts per side hold it securely to the frame.

The UA requires a winch as vehicle equipment, and further, cronies are expected to be on hand for recovery at all times. As such, cheap imported winches just don’t cut it, and when you need a winch, you need a winch. As such, we turned to Warn for one of its new Zeon winches. We went a little heavier than normal with Warn’s 10-S winch since we’ll likely be using the winch for recovery as much as self-extraction. The Zeon 10-S features 10,000 pounds of pulling power and includes 100 feet of synthetic 3⁄8-inch line, which is easier to handle during multiple extractions. Oh yeah, it looks pretty mean on the front of the bumper as well.

17 While we love the new winch, we’re not so sure about the new method of attaching the synthetic line to the drum. It involves pulling a loop through a very small hole in the drum and inserting a key to secure the loop. The recommended zip-tie method didn’t work for pulling the cable through, so we ended up using baling wire and even then it was a struggle. Stay tuned as we cover the rest of what it took to get this rig UA-ready next month, along with how it did on the trip.


Offroad Design
Warn Industries
Clackamas, OR 97015
Nitro Gear & Axle
Sacramento, CA
4 Wheelers Supply & Off Road Center
Phoenix, AZ 85034
Eaton Corp./Detroit Locker

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