How To Select The Right Accessory-Drive Brackets For A GM LS V8 Swap

Properly mounting engine driven accessories onto your LS V8 swap may at first seem much more difficult than anticipated. LS swap engine mounts, headers, and cross members, make it easy to install the engine in a variety of early model GM muscle cars and trucks. But adapting the A/C compressor, alternator and power steering pump to the LS V8, depends on which LS engine you’ve got, the accessories you’re using, and the amount of space left in the engine compartment.

Finding the bracketry to utilize the factory or aftermarket A/C compressor, steering pump and alternator can be both confusing and expensive. Because of this, manufacturers like Holley Performance decided to make it much easier to set up engine driven accessories, by using a new line of LS Swap Accessory Drive Brackets. These driver and passenger side accessory drive brackets allow the correct mounting location and proper belt alignment for vehicles with or without air conditioning, and incorporate the proper offsets so that they can be used with any GM LS water pump or crankcase balancer.

The LS Swap Accessory Drives feature a universal bracket that fits all common LS engines, regardless of the water pump and harmonic balancer the engine came with. The system can be used with commonly available GM A/C compressors (Sanden and GM R4) and positions it above the vehicle’s crossmember, but still allows it to fit under the hood. Then, depending on the crank pulley you’re engine is equipped with, and the accessories you want to mount on the engine, you can select from a variety of Holley’s accessory bracket kits.

Follow these steps to easily select the right accessory bracket kit.

1) Determine which crank pulley your LS engine is equipped with. Begin by taking a measurement from the crank pulley’s front edge (forward face), back to the pulley’s crank bolt surface. Three lengths were used on a variety of LS equipped GM vehicles. These are a 1.5-inch deep pulley (37mm), a 2.25-inch (55mm), and a 3-inch (75mm).

2) Match the pulley to the appropriate Holley Installation Kit.

*1.5-inch (37mm) = 21-1 Installation Kit

*2.25 (55mm) = 21-2 Installation Kit

*3-inch (75mm) = 21-3 Installation Kit

3) Then decide which Holley Universal Bracket Kit to use, depending on which A/C compressor and accessories you’re using.

* Holley 20-131 – For R4 A/C compressors and LS alternator and power steering pump. Includes driver and passenger side brackets.

* Holley 20-132 – For Sanden A/C compressors and LS alternator and power steering pump. Includes driver and passenger brackets.

* Holley 20-133 – For R4 A/C compressor. Includes passenger side bracket only.

* Holley 20-134 – For Sanden A/C compressors. Includes passenger side bracket only.

* Holley 20-135 – For LS alternator and power steering pump. Driver side brackets only. Not applicable to 1.5-inch crank pulley (21-1 Installation kit).

If you’re LS V8 swap didn’t come with any accessories, Holley has them available in a variety of kits that come with either an SD7 Sanden, SD508 Sanden, or R4 A/C compressors, 130 amp large-case alternator, Corvette aluminum power steering pump, belt tensioner, pulleys and belt.

So no matter what engine and accessory combination you have, you will be able to install the right brackets to properly align the serpentine belt and fit everything under the hood. While the Holley LS Accessory Drive brackets are easy to install, keep in mind you’ll have to install the steering pump pulley before bolting on the pump to the bracket. An insertion tool is also available that makes it easy, and can be rented from a number of tool and auto parts stores.

For more information on Holley’s LS Swap Accessory Drive brackets and other LS swap products, visit http://www.holley.com.

Additional Resources

Holley LS Accessory Bracket Fitment Matrix Chart

Diagram For Measuring And Identifying Your Crankcase Pulley

YouTube Video: Chucks Garage Installing Holley’s Accessory Drive System