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1972 Chevy Nova LSX Engine Swap - Modernized!
Transplanting A 5.3L LS Mill Into A '72 Nova
Henry De Los Santos
Nov 1, 2009
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1972 Chevy Nova LSX Engine Swap - Modernized!
From the start, it was really a matter of cleaning and removing the unnecessary parts, namely the stock wiring harness. David Stoker went ahead and removed the A/C compressor, since the engine mount is in the way and wouldn't clear the Nova's factory crossmember.
Utilizing Turn Key Engine Supply's engine brackets, the first order of business was to attach the new rubber mounts. Note: For our application, we had to grind away the boss on the back of the rubber mounts so it would fit flush to the adapter bracket.
From there we went ahead and removed the factory truck oil pan, windage tray, and pick-up tube, swapping them out for the ones supplied in the Turn Key conversion kit.
We also removed the factory throttle body and replaced it with a larger one from Turn Key. The 5.3L already had a vacuum port on the intake, along with the new throttle body, so one will eventually need to be plugged.
Up next, the 4L60E transmission was bolted onto the engine. When using a 700-R4, 200-4R, TH350, TH400, or any other transmission of your choice, you'll need to use the converter spacer/adapter that's included with the conversion kit.
Before we installed the engine and transmission, we had to install the correct V-8 engine brackets onto the crossmember. While these aren't supplied, the mounts are available from any number of aftermarket manufacturers.
To accommodate the robust 4L60E, we had to move the transmission mount back by approximately 2 1/2 inches. This will also need to be done for a 700-R4 or 4L60. The 200-4R needs to be spaced even farther, and all assemblies will require a shorter driveshaft.
Once the engine compartment was ready, we set the engine and transmission into place and bolted everything down.
To handle cooling duties, we installed a new radiator from Alumitech Reproductions. This was a complete drop-in piece featuring an integrated trans cooler, and Alumitech even accommodated us by installing an additional steam port bung for the cylinder heads. Also available is a complete electric fan assembly, but for the time being we decided to retain the factory clutch fan instead. Either option will work; it's a matter of preference and budget.
Since our Alumitech radiator maintained the factory dimensions, it allowed us to use the factory V-8 radiator hold-down. We also liked the fact that we were able to use the factory radiator hoses from the truck by simply cutting a couple inches out of each one. What's more, this will allow for quick fixes should we ever get stranded on the side of the road with a blown radiator hose.
From there we bent up new transmission cooler lines.
To prevent steam pockets from forming in the heads, we attached a hose from the cylinder heads and connected it directly to the steam port bung on the radiator.
Moving on to the fuel system, the conversion kit comes with a new inline fuel pump, a prefilter, and a filter after the pump. Since there's an infinite number of ways to set up your system, you will need to purchase the correct fittings to connect everything. Once you have the fuel lines plumbed, it's just a matter of running a power wire from the pump to the fuel pump relay in the engine bay.
Most LS engines have a fuel return line coming out of the intake manifold. Ours didn't. We later learned that '03-and-up 5.3Ls didn't have one. Fortunately we were advised to use a '99-and-newer Corvette fuel filter. These are an inline regulator/filter combination with a return line built in. By doing this, we replaced the filter supplied in the conversion kit and made our install even easier, since we didn't need to run a return line through the length of the chassis.
Dorman makes a fuel line repair kit that comes with factory-style fuel hoses and the tool to install the factory-style quick-disconnect ends. We used a combination of this and hard-line to run the new fuel line to the engine.
Admittedly, trying to figure out what headers work on a conversion like this can be a nightmare. Rather than guess, we went directly to Sanderson Headers and were shown a direct bolt-in performance header (PN LS150) with 1 1/2-inch diameter primary tubes with a 2 1/2-inch collectors for our application. Sure enough, everything cleared and fit like a glove.
Next on the list was to install the Turn Key harness. This simple plug-and-play harness may look intimidating at first, but it's well labeled and pretty easy to follow. The first thing to be addressed is mounting the computer, relays, and fuses. For this combination, we mounted the computer onto the firewall, right above the heater box. For the relays and fuses, we mounted them on the passenger-side fenderwell.
Once the computer and relays were mounted, we plugged the harness into the corresponding plugs on the engine. The harness also includes two O2 sensors, but requires O2 bungs to be welded directly into the exhaust. It's worth noting that our conversion kit even came with a K&N filter, but we weren't able to take advantage of it with the truck intake and accessories. Instead, Stoker plans to modify and reuse the factory intake ducting.
There are three relays in the harness, two for electric fans and one for the fuel pump. Realistically, we only needed the fuel pump relay; however, we went ahead and mounted the fan relays, giving us the option to use them down the road. All that's left is to run the power wire to the battery and accessory power for the computer and fuel pump.
Since we did away with the drive-by-wire assembly, we used a Lokar LS throttle cable. To install it, we used the supplied cable bracket from Turn Key and hooked it up to the stock pedal.
Finally, Stoker was able to move on to the little things to get this the mill up and running: the battery, power steering hoses (if applicable), shift linkage, adding fluids, and hooking up the car's factory wire harness to the starter and alternator for power. With the vacuum hose connected to the brake booster, it was only a matter of finishing up the exhaust.
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