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1991 Chevy Truck Engine Install - 4Wheel & Off-Road Magazine

1991 Chevy Truck Engine Install - When Cheap Ain't Cheap Fred Williams Brand Manager, Petersen’s 4Wheel & Off Road

Here's the scenario: You're looking around for a cheap project truck and find a 4x4 in the weeds, behind a barn, or next to the local garage. You glance underneath and find good running gear, plus maybe it's already lifted or has some muddies bolted on, but when you pop the hood you find out why it's sitting. The engine bay hides one of the following: a swapped-in or original engine that won't run, the stock engine but partially disassembled, or a gaping hole where the engine used to be. After a bit of negotiating with the owner you make the deal of the century and leave to borrow a trailer or call a tow truck in order to get your new "cheap" project home. It should be easy, right? Slap an engine in there, go wheeling, have fun, life is great...right? Sometimes.

1991 Chevy Truck front View Remove Engine Photo 9233602

We did exactly the above and thought we would be hitting dirt in no time, but like every project that needs to be done before we grow old and gray [or grayer-Ed.] it didn't just fall together. Hindsight has revealed many bits of wisdom that you should considered before dragging home a project without a running powerplant. First things first: The more complete the truck, the easier it will be to get it running. Even if the engine has been sitting for 50 years, if you have all the auxiliary parts then either rebuilding or replacing parts will be more trouble-free. Second is the concern of smog. That four-letter word devised to control the emissions of any late-model vehicle can be the bane of anyone engine swapping, upgrading, or rebuilding a four-wheeler. If at all possible, get a pre-smog truck to start with (for your area), because otherwise you can be chained to an iron ball requiring air pumps, catalytic converters, and miles of vacuum lines. Some smog-era trucks are so castrated for emissions that even a solid running big-block still feels like a Pinto (ask us how we know). And finally, if it has a computer you better have a healthy checking account. Computerized and electronically controlled engines and transmissions are great when new, but given 15-plus years of use, the deterioration of the switches, sensors, and plugs used to control and check up on them, plus multiple owners installing multiple grades of stereo, lighting, and security systems, can leave your cheap truck a rats nest of low-grade connectors, shorts, and mismatched wires. All of this can leave your computer-controlled 4x4 stranded or your checkbook smoking. Consider this the voice of reason reminding you that you truly do get what you pay for, and sometimes cheap can be expensive.

PhotosView Slideshow We got our hands on this '91 Chevy for under a grand. The story was that the previous owner wanted more power, pulled the engine to swap the cam, and then either got bored, ran out of money, or was lost on a expedition in the Amazon. The engine sat in the bed of the truck and started collecting rainwater and losing parts for a year or two, and eventually was passed on to a guy who knew a guy who knew us. We figured it just needed an engine and we'd be cruising in a 3/4-ton pickup, testing some IFS components, towing our more "extreme" trail rigs, camping in the bed, and best of all owning a late-model truck with fuel injection, an overdrive automatic, and plenty of room inside for long journeys off-road. Of course the list got longer than "just an engine" really quickly. We decided that with nearly 200,000 miles on the big-block plus years of rainwater in the cylinders that a rebuild or replacement was in order. We chose a GM Goodwrench long-block engine for a handful of reasons. First is the ease of installation. This 454 (7.4L) engine is identical to what came out of the truck so the accessory mounts, intake and exhaust manifolds, and transmission flywheel will all bolt right up. Plus, this is a brand-new engine block and internals. Next was the time frame. We really didn't want to go through the process of getting either the old engine torn down and inspected (it later turned out to be beyond repair) or a salvage-yard block gone through and built; we just wanted to put an engine in the truck and get it dirty. The final argument for our new long-block is the Goodwrench warranty. It comes with a three-year, 100,000-mile coverage that includes engines installed at home or at some non-dealership shop. There are certain restrictions such as no racing or competition use, plus it doesn't cover damage caused by mistakes in installation, misuse, or lack of proper maintenance, but that all seemed reasonable. So we got on the phone with the crew at Pace Performance in Niles, Ohio, and quickly had a shiny new big-block long-block sitting on our doorstep. List price was just under $4,200. Pace also has an awesome catalog of truck accessories from lights to running boards so be sure to get on the mailing list. When our new block was ordered from Pace, we planned to bolt on all the original parts, so we started looking through the piles in the bed of the truck and behind the seat in the cab. We collected a bunch of bits, and began to notice that everything needed to be rebuilt or replaced. The starter and alternator were used as cores for rebuilt units ($150 alternator, $80 starter), the A/C compressor pump and lines swallowed up another $400, and the throttle body looked unrebuildable. Luckily we found Turbo City, which specializes in throttle-body rebuilds and upgrades as well as wiring harness repair and custom computer programming. We like the simplicity of throttle-body injection, and Turbo City was not only able to save ours, but also upgraded it with a new fuel-pressure diaphragm and throttle shaft. In addition, Turbo City cleaned and flowed the injectors. They also tested all the sensors. If you are looking for upgrades they can also supply throttle-body spacers, air intakes, and adjustable fuel-pressure regulators. A basic rebuild ranges from $75 to $400 depending on the condition of your throttle body. We banked on the big-block having sufficient power and torque, but we wanted to make sure that it also was reliable for long hauls whether in Mexico or Manhattan. To that end, one of the only upgrades we added to the engine was an Edelbrock Victor series water pump. These water pumps help dissipate heat better by using a cast-aluminum case, as well as pumping a larger volume of coolant at a greater velocity and evenly distributing it to both sides of the engine. Plus by using a heavy-duty seal and larger-than-stock bearings it should outlast a stock-style pump. The cost for the cast finished piece is twice the cost of a stock unit at around $175 (polished versions are more than $300), but the investment in a cooler running truck is worth it. In order to get the engine all assembled and installed in the truck in a timely manner, we took it to the folks at GM Truck Center in Burbank, California. GMTC offers many different options from restorations to modification for your GM truck, and spending the time to correctly install an engine is right up their alley. This brings up another great insight on any engine installation: Having someone there to either do the job for you or just look over what you are doing is a great help...especially when you are assembling an engine that has been disassembled and some parts are either missing or not obviously cataloged. We had the entire engine neatly assembled on an engine stand before we swung it into place. Another problem we encountered was that nearly all the fasteners were missing, plus this era of engine requires a mixture of metric and standard hardware. We decided to replace as many items with new as we could track down and fit, and found that many companies offer fairly complete engine fastener kits, especially for General Motors V-8 engines. Companies such as ARP offer kits that include intake manifold bolts, valve cover bolts, thermostat housing bolts, alternator bracket bolts, distributor bracket bolts, motor mount bolts, oil pan bolts, coil bracket bolts, header bolts, front cover bolts, water pump bolts, and fuel pump bolts. PhotosView Slideshow Our TBI 454 runs an onboard diagnostics system that, combined with the engine management system and standard monitoring for gauges, requires the block, heads, intake, throttle body, and exhaust system (not to mention transmission and transfer case) to have a fair number of sensors. We decided that the best bet was to replace every single one rather than gamble that they might still work. In many cases we had no choice but to replace them since many of the old sensors had been broken. We also found that for every sensor there is also a specific plug on the wiring harness and more than a few of them were broken or cracked from aggressive removal. Unfortunately, a factory replacement wiring harness is no longer available, so we are running our current connectors, but plan on returning to Turbo City in the future to repair any wiring problems. We decided to cross our fingers and leave the transmission and transfer case alone for the time being, though hindsight proved this to be a losing gamble. We did at least run a tap through the threads into the torque converter/flywheel mounting points, but would recommend that if you don't know the status of your automatic and already have the engine out, you may as well pull the trans and have it gone through. With the hood removed, the engine is easily inserted into the truck when hung from an engine hoist with a tilting engine bracket. Recruiting a friend or two to keep an eye on all the accessories, wires, and hoses that can get caught and torn doesn't hurt either. Once the engine is sitting in the motor mounts and lined up with the transmission indexed onto the clutch, or in our case the torque converter, it is time to start hooking everything up. Our cheap truck was missing many parts, not the least of which was the radiator. We ordered one from Extreme Radiator and what arrived looked better than new. We knew it wasn't going to be cheap because the copper brass assembly not only drops the coolant temperature, but also has a built-in oil and transmission-fluid cooler. While we would recommend Extreme Radiator for your replacement cooler needs, they also specialize in radiators for engine swaps for those of you looking to put a V-8 in a Jeep. In front of the radiator we installed a new air-conditioning condenser also from Extreme Radiator. It fit perfectly, but before we hooked up the A/C system we took the truck to Burbank Radiator to have the entire A/C system flushed and charged. We figured that having a cool breeze blowing would be great for trips to the desert, but again wiring glitches arose and we have not yet gotten the in-dash control to light up right. Hopefully by the time this issue hits the newsstands we'll be chillin. Another benefit of working with a shop like GM Truck Center is the fact that they have specialized tools on hand that make the job much easier. Here Vachik Rostanlou tightens down the distributor with a set of distributor wrenches. Another expert device we used was a set of exhaust manifold spreaders that, when applied with some heat from a torch, allowed us to easily line up the bolt holes in our split cast-iron exhaust manifolds. A very important part of getting our low-buck fullsize up and running was finding a quality auto parts dealer to work with. We have some new friends at the local Burbank Auto Parts as we visited daily for this install and they were top notch to work with. It's nice to find a counterman who knows how to find what you want without needing the VIN of your truck just to turn on his computer.