LS1 Swap - How To Swap A Gen III Into A '64-'72 A-Body Part II

For the test runs, we used... 

   

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For the test runs, we used 87-octane pump gas, the fuel, timing, and transmission maps that were preinstalled on the Keisler A41 transmission, and the MSD MEFI4 engine controller.

In the May '08 issue, we dropped a GM LS1 into a '64 El Camino and left you hanging because we didn't have the parts to finish the job. Since that time, we've received exhaust, a radiator, and all the little parts and pieces to get the car on the road. In March, we drove the Elco to Ramona, California, near San Diego on the Car Craft Anti Tour, getting nearly 20 mpg on the way with zero overheating and zero drama. In fact, the car is so reliable, it might be bordering on boring. It's a good problem to have.

The Keisler A41 is similar... 

   

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The Keisler A41 is similar to a 4L60E GM overdrive. Since we were using the stock LS1, we used the Stage 1 model with a 1,600-2,000-rpm lockup converter that is rated for no more than 450 lb-ft. The A41 is 30 percent overdriven, putting us at about 2,000 rpm at 70 mph.

The following details cover the rest of the installation and the scary computer stuff that really wasn't scary at all. We ended up using the base maps provided by the manufacturers and included some info on how to tweak them if you want to bark the tires and waste some fuel. It reminded us just how easy it is to build a Chevy.

There are only two connectors... 

   

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There are only two connectors that will be plugged into the transmission: the 2-pin vehicle speed sensor (VSS) on the tailshaft and the 13-pin connector on the main body. Both connect to the transmission control unit (TCU) we mounted under the dash. We also connected the 12-volt key-on ignition source, the ground wire, and the brake switch connector to tell the converter to unlock when the brakes are applied. That's all there is to it.

There should be a Mexican restaurant called The El Camino, if there isn't one already we're just sayin'.

The Windows-based Keisler...        read full caption The Windows-based Keisler interface allowed us to simply upload any of the three supplied shift maps, or we could fiddle with shift points, firmness, and the lockup converter live. By the time you read this, Keisler will have added a toggle option so you can flip to the performance map using a switch. It shifts later and harder and doesn't lock up the converter if you are drag racing.	Our engine didn't come with...        read full caption Our engine didn't come with a stock starter, so we tried the LS starter from MSD. We did it for two reasons: Whenever we cheap out on the starter when we install a new engine, it fails; and the MSD starter is clockable, so we knew it would fit in any position with any headers. So far, we are unscarred from the experience.	The A41 uses throttle-position...        read full caption The A41 uses throttle-position information to set shift timing and line pressure. As the voltage signal increases from 0.45 to 5.00 volts, line pressure increases and the shift is delayed according to the program that is installed. Therefore, it is important that the throttle position sensor (TPS) is connected to the transmission wiring harness. If you are using a carburetor, Keisler supplies a TPS kit with a mounting bracket.
To keep the transmission cool,...        read full caption To keep the transmission cool, we used a B&M Hi-Tek automatic transmission cooling system. It consists of a cooler with a Spal fan and a 160-degree thermostat that is self-contained, or you can control it with a factory engine computer or the MSD MEFI4.	The MSD engine controller...        read full caption The MSD engine controller has a big, fat wire for the tach, so we couldn't resist buying some new candy: This is the 50th anniversary short sweep pedestal tach from Auto Meter. Note the correct hose-clamp installation.	The '04 GTO that gave up this...        read full caption The '04 GTO that gave up this engine uses a cable-driven throttle body. After looking at several Gen III swaps, we discovered the LS1 cable from Lokar. It is the simplest way to connect to a throttle on a musclecar. It even comes with the bracket.
The transmission comes with...        read full caption The transmission comes with a speedometer gear of your choice, depending on the wheel and tire combo and rear gear you have, or you can use an optional electronic speedometer output for electronic gauges.	Probably the coolest part...        read full caption Probably the coolest part of the swap is the overdrive shift indicator. Notice the circle around the D? You have to be paying attention.	Another problem we solved...        read full caption Another problem we solved using street rod parts was the gas pedal. The factory Chevelle/El Camino pedal arm interferes with the cylinder head under the hood, preventing the throttle from opening more than 80 percent. The new pedal allowed 100 percent throttle opening for better burnouts and harder shifts.