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How to Swap an LS into an LT1 Fourth-Gen

One Letter Off: Everything you need to know about swapping from an LT1 to an LS1 in your Fourth-gen

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Over and over again we've heard people ask about swapping from an LT1 to an LS1 in their Camaro. How hard could it be? The LT1 and LS1 fourth-gen Camaro is essentially the same car. While there is certainly some truth to that, the differences can come back to bite you when you attempt to swap an LS of any sort into an LT1 Camaro. But it is certainly not impossible, and if you have already invested some money into your LT1 Camaro's chassis, it may be worth your while. I will let you be the judge as we cover the essentials of making this swap a reality.

The first thing you need to be aware of is that the motor mounts are different from the traditional small-block to the LS1. The easiest solution is to source a stock K-member (and engine stands) from a wrecked 1998-'02 Camaro Z28 or SS, or to purchase an aftermarket tubular version. If you decide to purchase polyurethane motor mounts, remember that these typically do not include the metal clamshell that actually bolts to the block. Those you'll need to purchase from a Chevy dealer or someone like Hawks Third Gen Parts. The control arms, spindles, brakes, etc. can be recycled, thankfully—so that saves you a few bucks. The exception, though, is the steering rack and linkage.

Even though the transmission options are the same (T-56 or 4L60E), there are some differences between the two that prevent a direct bolt up. The electronics on 4L60Es vary even within LS versions, let alone to the LT1. However, according to Greg Lovell at AntiVenom, the easiest solution is to keep the unit you have and use a custom torque converter to match the LS1 flexplate and the early style input shaft. FTI and Circle D are two popular choices of custom converter suppliers that accommodate those needs. A good torque converter ups the fun factor and drop e.t.'s, so why not use the opportunity to make an upgrade? The T-56 uses a much different clutch and hydraulic system on the LT1 version as well as a different bellhousing and mid-plate. It can be converted, but unless you have already invested some money into internal upgrades you might as well sell or exchange it for a rebuilt LS1 version. Crossmembers and driveshafts are virtually interchangeable between years so there should be no concern there. However, the weak steel driveshaft on the automatic should really be swapped out for an LS1 or aftermarket version.

The accessory drive system is a major departure from the LT1. Pretty much nothing is reusable. And remember that the F-body uses a unique accessory drive arrangement. Only the 2004-'06 GTO shares it. C5/C6 Corvette, Fifth-gen, or truck parts are not going to cut it—starting with the balancer and water pump. Hawks Third Gen sells brand-new alternator brackets, idlers, and power steering reservoirs as well as complete take-out engines with accessories. In case you are wondering, the old alternator, power steering pump, and A/C compressor and lines can't be reused. It pretty much goes without saying, but of course I have to, that the exhaust system and air intake must also be considered. You can mate a set of LS1 headers or exhaust manifolds and Y-pipe up to the old cat-back exhaust. However, using a traditional LS1 air lid requires the lower part of the airbox that doubles as a radiator cover. If you can't find this piece, K&N's cold-air kit comes with its own radiator cover.

While an LT1 fuel pump (in perfect condition) should provide enough output for a relatively stock LS1, despite the jump from around 42 psi to 58 psi fuel pressure, at this age it is not recommended. Racetronix offers drop-in solutions that will support over 600 rwhp as well as a plug-and-play wiring harness that connects directly to the alternator for power. Not only is your wiring brittle by this point, but it can't properly support the electrical load of an aftermarket pump. The fuel lines themselves are another consideration. The LT1 fuel system is a standard return system with a regulator on the fuel rail, while nearly all LS engines are return-less. AntiVenom recommends using the 1997-'98 Corvette fuel rails with their built-in regulator to reconcile this. Of course, if you can't locate a used one for a reasonable price, aftermarket options might be a better course.

The last major hurdle is the electronics. Assuming you have all the necessary sensors (including the MAF, knock sensors, IAT, MAP, etc.), you can't simply plug an LS1 F-body wiring harness and PCM into the Camaro and go. The plugs for the dash and Body Control Module (BCM) are different. If you are handy with wiring diagrams and crimpers, you can certainly convert an LS1 engine harness yourself. However, the folks at Current Performance are one of a few companies out there that will take the headache out of the conversion. Having modified existing harnesses (a cheaper option) and built them from scratch for many years, Current knows exactly what to expect and how to handle the issues that can grind your project to a screeching halt.

The one thing to keep in mind is that every swap is different. After having perused many Internet forums and spoken with a few people who have done them, there always seems to be a unique issue that didn't come up on others—whether it was getting the starter to crank, cruise control to work, etc. This is especially true as you start throwing aftermarket parts into the mix. Hopefully this story will at least give you the basic information to get started, and the awareness to help identify any potential issues. Happy swapping!


Engine Swap Replacing Rubber Bushings 2/24

1 If your LS engine came with a set of motor mounts on it, you can replace the rubber bushings inside with urethane if you prefer. If it did not, you will need to purchase a set like this from Summit Racing (PN ANI-3064, $53.97) or a local GM supplier that comes with the clamshell to actually bolt to the motor.

K Member For Camaro Engine Swap 3/24

2 If you can find a reasonably priced stock K-member from a 1998-'02 Camaro Z28 or SS (or Firebird), that will be your foundation for the LS swap. You'll need to use an F-body oil pan, flexplate, water pump, and harmonic balancer.

K Member Motor Mount Stands 4/24

3 One important note: make sure the K-member comes with motor mount stands to bolt to the motor mounts.

Summit Racing Tubular Aftermarket K Member 5/24

4 If supply or weight is a concern, Summit Racing sells tubular aftermarket K-members like this one from BMR (PN KM003R, $579.95) that comes with motor mount stands. Some versions do not have the stands, some are for other engines (SBC or BBC), and some are for manual steering racks. Make sure you choose the right one.

Lt1 Steering Rack And Linkage Not Fitting 6/24

5 The LT1 steering rack and linkage will not fit, so make sure you source a used or rebuilt 1998-'02 Z28 version. The linkage can be purchased from a local parts store.

Installing Ls1 F Body Accessory 7/24

6 If you do not have LS1 F-body accessories, you can piece together most of what you need through Summit Racing and your local parts store. Hawks Third Gen has also proven to be a good source for these pieces, including whole take-out engines with accessories.

Chevrolet Performance Belt Tensioner 8/24

7 Summit Racing's Make/Model input on its website makes finding some pieces like this Chevrolet Performance belt tensioner (PN NAL-12560344) easy to find.

Tuff Stuff Power Steering Pump 9/24

8 Summit also carries Tuff Stuff power steering pumps (PN TFF-6175AL-6) if you are looking for an upgrade over a used OEM piece.

Summit Racing Springs 10/24

9 One last note before you bolt that K-member up to your Camaro, you may want to consider upgrading the front springs. If you are using an aluminum block LS engine, it will be quite a bit lighter than the LT1 it replaced. Reusing the old springs can make the car feel "darty," so Greg Lovell at AntiVenom recommends swapping them for stock 1998-'02 Z28 (or SS) springs or even lowering springs. Summit Racing sells these front springs (PN SUM-720104F) for just $50.99, so why not do a little upgrading?

Stock 4l60e Bolting Onto Ls1 11/24

10 Thankfully the stock 4L60E will bolt up to the LS1, though it uses a different plug and converter than the LS1 version. The easiest solution to the converter issue is to pick up a custom converter that will bolt up to the LS1 flexplate and slide onto the older 4L60E's input shaft. You could swap out the converter and transmission if you wanted to use stock parts, but a custom converter will simplify the swap and up the fun factor.

Lt1 Clutch And Front Plate 12/24

11 The LT1 T-56 uses a much different push/pull type clutch with a mechanical fork, so the front plate (aka mid-plate) is easy to tell. The LT1 clutch and front plate are not compatible with LS engines.

Transmission Needing To Be Swapped 13/24

12 To swap to an LS engine you will either need to convert the old style trans with a kit from Rockland Standard Gear or sell it to buy an LS version like these from an F-body or GTO. Some transmission builders may let you exchange your LT1 unit for an LS1.

Installing F Body Starter Kit Components 14/24

13 An F-body starter is required for the swap, though some may have gotten away without it. Greg Lovell at AntiVenom suggests this, along with the water pump and balancer, as one of the areas where it is best to buy new to save headaches later.

Summit Racing F Body Headers 15/24

14 There is no shortage of options when it comes to F-body headers, so log on to www.summitracing.com to select the set that best fits your needs. But don't forget to get a matching Y-pipe so it will bolt up to your cat-back exhaust.

Installing Y Pipes 16/24

15 Y-pipes are available with or without catalytic converters. The "off-road" version can save you money if emissions compliance isn't an issue.

Fuel Rail 17/24

16 AntiVenom suggested using a 1997-'98 Corvette fuel rail rather than the LS1 F-body fuel rail, which has no return to the fuel tank. Otherwise, you will need new fuel lines and a new tank. Racetronix sells the quick-disconnect PTFE fittings and braided hose you'll need to mate the 3/8-inch feed and 5/16-inch return lines to the fuel rail. If you can't find a used Corvette fuel rail at a reasonable price, it will be cheaper to contact Racetronix for a full setup. Jack at Racetronix estimated $120 in just adapter hoses for the C5 rails versus $211 with rails, regulator, and liquid-filled gauge.

Conversion Fuel Pump 18/24

17 If you still have a stock fuel pump in your 19- to 23-year-old Camaro, it is time for a replacement. Racetronix sells this 255-lph turbine style fuel pump (PN RXP255) with a Walbro/GM Teflon in-tank harness for the LT1 tank. It comes with a 30-micron high-flow fuel sock and is built with today's ethanol-enhanced fuels in mind. The fuel pump wiring harness upgrade is a great idea since the brittle factory wiring can't handle the electrical load of an aftermarket pump.

Replacement Hoses And Lines 19/24

18 While we have covered the basics here, it is important to note that some of the hoses and lines will need to be replaced—including the A/C lines and coolant hoses.

New Radiator Cover Air Intake And Maf Sensor 20/24

19 To wrap up the mechanical side you will need a new radiator cover, air intake, and MAF sensor. K&N's cold-air intake solves two of those issues.

Efi Connection Engine Harness 21/24

20 This engine harness was made by EFI Connection to adapt the LT1 to an LS1 PCM. The harness needed to make your gauges, accessories, and old 4L60E function with an LS1 engine isn't that much different. EFI Connection is another source for custom wiring harnesses and the parts needed to make your own. Also note: if your LS engine is missing knock, water temp, IAT, MAP, and other sensors, you will need to source those as well to match the harness and computer.

Installing Efi Connection Engine Harness 22/24

21 A properly made harness will have all the right connections to the transmission, gauges, and Body Control Module (BCM). It threads through the firewall behind the A/C lines and heater on the passenger side.

Feeding Cluster And Bcm With Wiring Plugs Under Dash 23/24

22 Underneath the dash, the wiring plugs in to feed the cluster and BCM. This is a crucial step because many sensors and functions of the chassis and interior are connected. Side note: if you have a 1993-'95 Camaro, you will want to install an OBD-II port so that you can tune and scan the PCM just like a 1998-'02 Camaro.

Bolting On Pcm 24/24

23 Last but not least, the PCM will be bolted into the same location in the engine bay and the wiring harness is plugged in. Consult a reputable tuner for a calibration that will have your Camaro running like a top.


More LS Swaps

Converting a Fourth-Gen V-6 to an LS Engine

Golen 383 & EFI Connection LS1 PCM Swap - Heart Attack, Part 2 - Tech

Sources

Summit Racing
Akron, OH
800-230-3030
http://www.summitracing.com
AntiVenom
Seffner, FL 33584
813-381-3995
www.antivenomefi.com
Hawks Third Generation
Easley, SC 29640
864-855-2694
www.hawksthirdgenparts.com
Current Performance
Port Richey, FL 34668
1-727-844-7570
www.currentperformance.com

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