LS Engine Pulleys - LS Accessory-Drive Swap Guide
Bolting A Gen III/IV Engine In To An Early GM Muscle Car Isn't Difficult, But There Are Some Shortcuts That Can
Save You Time, Money, And Hassle...
By Jeff Smith
Photography by Jeff Smith, Roger Kunkel, Troy Matos
Accessory drives have always been a hassle when it comes to engine swapping, but armed with this
information, your choices become much easier and less expensive.
One of the hottest engine swaps in our world right now is the Gen III/IV (or LS, if you prefer) engine
transplanted into a '60s or '70s GM muscle car. These engines not only are more powerful than the old Gen I
small-blocks, but they're also lighter, don't leak, are easier to work on, and are far more efficient. It's
everything a car crafter could want, but swappers have discovered that these engines don't bolt in to a
Camaro, Chevelle, or Nova without modifications. While there are quick and expensive ways to mount an
alternator, power steering pump, and air conditioning compressor, our goal is to show you how to do this
while watching that budget. The good news is that you can get what you need without having to spend big
dollars. It all depends on how trick you want to get.
GM Accessory-Drive Layouts
All factory GM systems place the alternator and power steering pump on the driver side with the A/C
compressor mounted low on the passenger side driven by a separate belt. Within this basic layout, there are
three significant variations based on whether the system was designed for a truck, the original LS1
Camaro/Firebird platform, or a Corvette. As for the A/C, all three systems mount the A/C pump in generally
the same spot, but the mounts are not interchangeable.
The Corvette drive is the tightest to the front of the engine and places the alternator on top with the power
steering pump underneath. This arrangement is wider at the top, offering maximum clearance toward the
bottom of the engine. The next system was used on the Camaro/Firebird and early CTS-V Cadillacs that
employ a harmonic balancer that projects out farther than the Corvette. This drive system places the power
steering pump on top on the driver side with the alternator positioned underneath. The third orientation is
the truck/SUV that uses the deepest balancer, pushing the accessory drive the farthest forward on the engine.
The truck orientation is the narrowest and tallest of the three drives with the alternator up top and the power
steering pump underneath. The truck system is the most common of the three but is the least visually
attractive. It may also present hood clearance problems on cars with low hood lines. It cannot be used with
any passenger-car LS EFI intake manifold because of interference between the throttle body and the idler
pulley.
We also discovered a glitch where an F-car-style factory alternator bracket bolts to an aluminum 5.3L block
(and we'll assume most other aluminum blocks), but when we tried to bolt it to an iron 6.0L block, there was
one missing bolt location on the block and another that was not drilled or tapped. It's unclear whether this
missing bolt hole extends to all iron blocks. Roger Kunkel sent us a photo of his solution based on an F-car
alternator rear mount location, leaving the missing bolt out of the front mount.
While we have not performed this swap, it does appear that a Gen III LS1 F-car accessory drive, for example,
will bolt on to the later LS2 or LS3 engines (Gen IV) as long as the F-car balancer is used. Also keep in mind that
if you change balancers, you must follow the factory-recommended procedure for torquing the factory
balancer bolt. The spec requires an initial torque of 37 ft-lb and then using the torque angle method to tighten
the bolt an additional 140 degrees. This technique applies to the one-time-use torque-to-yield GM bolt. If you
plan on lots of swaps, consider going to a reusable ARP bolt.
Harmonic Balancer Depths
The following chart lists the dimensions of the three different pulley depths used on the Corvette,
Camaro/Firebird, and truck accessory drives. We've listed two different ways of measuring these, both with
the balancer on the engine and on the bench. The depth of balancer dimension is measured from the rear of
the balancer hub to the leading edge of the balancer/pulley (overall depth), which can be used to identify a
balancer not mounted on an engine. We also included the depth from the front cover to the front of the
balancer if it is installed on the engine.
Depth Of
Depth Of Balancer
Balancer (Inches) (On Engine) (Inches)
Corvette
3 7/16
2 1/8
Camaro
3 13/16
2 15/16
Truck
4 3/8
3 11/16
Balancer
What Fits--And What Doesn't!
The main focus of this story is to give you an idea of which factory-available accessory drives can be used for
engine swaps. But just as important is which factory configurations don't fit. The difficulty with generic
information like this is it all has to be qualified with a bold-faced "it depends" because of the multiple fore/aft
locations for LS engines in muscle car chassis. Not all engine conversion mounts place the engine in the same
location, so be aware of this major variable. For example, the Street & Performance, ATS, and Morrison
mounts (and probably others) locate the engine in the same position, but the Hooker mounts (for early
Camaros and '68 to '72 Novas as an example) locate the engine roughly an inch farther aft. The BRP mounts
raise the engine up and also push it much farther forward. In the interest of available space, we'll save these
details for a later story. In this sidebar, we deal mainly with Gen III/IV alternator and power steering packages.
As for the factory A/C pumps, in most cases the factory A/C compressor will not clear the chassis without
notching the engine crossmember.
The '64 to '72 GM A-body cars include Chevelle/Malibu, Pontiac Tempest/Le Mans/GTO, Buick Skylark/GS,
Olds Cutlass/F-85, and since the early '70 to '72 Chevy Monte Carlos are based on an A-body chassis, these
cars should also be similar to Chevelle fitment details. For all these cars, the factory Corvette accessory drive
will clear all suspension and steering components. The downside is that this system tends to be hard to find
and expensive. Camaro-based accessory drives don't fit Chevelles because the alternator crashes into the
steering box. The truck drives will work if modified with a 5-inch-diameter power steering pump pulley to clear
the steering box, but most car crafters shy away from this system for aesthetic reasons, since the alternator
sits very high.
For early '67 to '69 Camaros/Firebirds and '68 to '74 Novas with a factory front subframe, either the F-car LS1style or the Corvette drives will fit, although the F-car alternator is snug. If you're using the Hooker mount kit,
you will have to notch the engine crossmember to clear the alternator. The truck accessory drives are way too
tall to clear the low hood line while, again, the Corvette accessory drive will bolt right on if you're fortunate
enough to own one of these systems.
The most important change for the second-generation ('70 to '81) Camaro/Firebird is that these cars
converted to front steer, moving the steering box in front of the axle centerline like a Chevelle. This makes
fitting the F-car LS1 accessory drive, with its low alternator, tight. It will clear the steering box, but clearance is
minimal depending on which engine mounts are used. The Corvette-style drive will clear everything, while the
truck system will not fit under the stock hood line. As with the other body styles, the A/C will only work if it is
relocated up high on the passenger side.
For those considering an LS engine into an '82 to '92 Camaro, the F-car accessory drive will bolt in without
serious modifications except that the factory A/C compressor will only clear with a notch in the engine
crossmember. In terms of other later-model swaps, it appears that swapping an LS-style engine into a C4 also
has significant merit. As for an accessory drive, it appears that a Corvette (Y-car) front dress will work.
GMPP Kits
Accessory drives are some of the most difficult components to design on an engine, and no one does it better
than the factory. GM spends thousands of dollars ensuring these systems are not only reliable but also quiet
and easy to repair. To take advantage of this, GM Performance Parts now offers two different accessory-drive
kits that offer all the necessary components to bolt on a complete system to the front of a Gen III/IV engine.
The 19155066 kit is configured like the older F-car or Camaro/Firebird LS1 engine drives but is actually an '06style Cadillac CTS-V arrangement. The catalog calls out the 19155067 system as designed for the LS2 and LS7
engines, but it will work on most all Gen III/IV engines as far as we know. This system is based on a Corvette
configuration. Both kits include an A/C compressor along with all mounts, bolts, and belts. For those who don't
need an A/C pump, there's a rumor that GMPP will soon release a new system without the A/C compressor to
trim the price even further. The best part about the current systems is the $825.85 price tag. We priced the
parts individually and the cost more than doubles, so the value is already high.
Power Steering Pumps
There are two types of power steering pumps used on the Gen III/IV engines. Trucks use the original Saginaw
Type I pump with its integral metal fluid reservoir, while passenger cars use the newer Type II power steering
pumps. There are also two different Type II pulley shaft diameters at 0.660 and 0.750 inch. Some information
points to the smaller diameter as used on Corvettes, but we've purchased several passenger-car Type II pumps
that use the 0.660-inch shaft diameter.
The factory parts necessary to mount a plastic factory remote reservoir system are expensive at around
$100.00, and the part numbers can be found on Kwik Performance's website under Tech Tips, but there are
alternatives. You can create a custom remote reservoir using AN lines and fittings for roughly the same price.
If you are building your own remote reservoir system, the return line should be a minimum of 5/8-inch id,
while the high-pressure side is normally a -6 AN.
The last variable is power steering pump pulleys. We've found there are many different pulley diameters,
depending on the application. A smaller pulley offers more clearance, but it also increases pump speed,
especially at idle. Changing pulley diameters will also require a new serpentine belt.
Kwik Performance
The problem with most aftermarket accessory drives is the entire system ends up costing a lot of money-anywhere from $850.00 to $2,500.00, so we began searching for a low-cost alternative, which turned up a
new company called Kwik Performance. As a SEMA member, Kwik had access to GM's CAD drawings of the
Gen III/IV engines and used these specs to create a new generation of accessory drive pieces that solve many
of the problems associated with swapping a Gen III engine into early muscle cars. Kwik created three kits
based on balancer dimensions for trucks, F-cars, and Corvettes. One big advantage of this idea is it eliminates
the purchase of a new balancer. So if you have a truck engine, you can purchase a Kwik alternator and power
steering mount kit for $287.00 that will bolt directly to your existing engine and clear the chassis. We did the
math to get an idea what the total cost would be to convert a truck accessory drive for use in an early
Chevelle. The kit allows you to retain the use of a truck or F-car-style alternator, and the truck accessory drive
will require a Type II power steering pump and pulley, but that's the only major requirement. You'll also need
a power steering pump pulley. We found several at the junkyard on '90s V-8 Cadillacs for $5.00 each. A new
factory reservoir package will run another $100.00 , so we decided to do a remote reservoir that can use AN
fittings with a nice aluminum tank from Summit Racing. Street & Performance, among many other companies,
offers custom-made power steering hose kits for your application.
A Cheaper Way To Do It
Description
Kwik alternator, P/S drive, truck
A-1 Cordon P/S pump
Typical serpentine belt
Summit aluminum remote reservoir
16 mm to AN -6
Press in to -8 AN
Summit 3-foot-length -8 hose
Summit 3-foot-length -6 hose
Power steering pulley
Painless alternator adapter
Total (your price may vary)
General Parts List
Description
PN
March alternator, P/S 20050
Concept One
alternator, P/S, A/C
Billet Specialties
alternator, P/S
Street & Performance
alternator, P/S
GMPP LS1/LS6
accessory drive
GMPP LS2/LS7
accessory drive
Kwik alternator, P/S
drive, Camaro
Kwik alternator, P/S
drive, Corvette
Kwik A/C bracket, Fcar
Kwik A/C bracket,
Vette
Kwik A/C bracket,
truck
Car Shop alternator
bracket and alternator
A1 Cardone water
pump, F
Source
March
Performance
LSV01M Concept One
13405
PN
K10168
20878
K060775
340202
991955
call
230803
230603
1636993
30705
Price
$2,395.00
$2,375.00
Summit Racing $2,089.95
N/A
Street &
$958.35
Performance
19155066 Scoggin-Dickey $825.85
19155067 Scoggin-Dickey $825.85
K10167
$287.00
9998
Kwik
Performance
Kwik
Performance
Kwik
Performance
Kwik
Performance
Kwik
Performance
Car Shop Inc.
58563
Rock Auto
$92.99
K10166
K10156
K10143
K10163
$287.00
$197.00
$197.00
$197.00
$550.00
Source
Kwik Performance
Rock Auto
Rock Auto
Summit Racing
Summit Racing
Street & Performance
Summit Racing
Summit Racing
Used
Summit Racing
Price
$287.00
$45.79
$26.79
$80.95
$6.25
$15.00
$15.95
$14.95
$5.00
$25.95
$523.63
GM P/S pulley (0.750 10166335 Burt Chevrolet
shaft)
Dorman Corvette
594115 Rock Auto
balancer
Dorman F-car balancer 594127 Rock Auto
Bosch truck
AL8730N Rock Auto
alternator, 105 amps
GM LS1 balancer bolt 12557840 Scoggin-Dickey
GM balancer bolt
12600525 Scoggin-Dickey
washer
ARP balancer bolt and 234-2503 Summit Racing
washer
$44.00
$73.79
$51.89
$155.79
$4.44
$16.66
$27.95
SOURCES
American Touring Specialties
Las Vegas, NV
702/245-6305
T56kit.com
Kwik Performance
Springfield, MO
417/955-1467
kwikperf.com
Billet Specialties
La Grange, IL
800/245-5382
billetspecialties.com
March Performance
Naples, FL
888/729-9070
marchperf.com
BRP Muscle Rods
Cumming, GA
770/751-0687
brphotrods.com
Painless Wiring
Fort Worth, TX
817/560-8324
painlessperformance.com
Burt Chevrolet
Englewood, CO
800/345-5744
burt.com
Rock Auto
Madison, WI
866/762-5288
rockauto.com
Car Shop
Moline, IL
309/797-4188
carshopinc.com
Street & Performance
Mena, AR
479/394-5711
hotrodlane.cc
Concept One Pulley Systems
Cumming, GA
877/785-5397
c1pulleys.com
Summit Racing
Akron, OH
800/230-3030
summitracing.com
GM Performance Parts
Warren, MI
800/577-6888
gmperformanceparts.com
This is the stock configuration for the Camaro/Firebird accessory drive found on '98 to '02 F-cars minus the A/C pump.
The easiest way to spot this design is by the power steering pump on top on the driver side with the alternator below.
This is also the drive arrangement for the GMPP kit PN 19155066.
The typical Corvette LS1/LS6 accessory drive layout places the alternator on the top of the driver side with the power
steering pump located below. This is also the orientation for the GMPP kit PN 19155067.
This is the truck accessory drive arrangement that is very tall. We measured this setup on our '66 Chevelle, and the
alternator will just barely clear the hood. If you're looking for the least expensive system that will bolt in place in a tall
engine compartment (like a '55 Chevy), this is a good choice. If the engine is fuel injected, this drive system requires
using a truck intake manifold, since the car throttle body won't clear that top idler pulley.
This is a factory F-car alternator mount bolted to an iron 6.0L block using a rear support bracket. Roger Kunkel used this
factory accessory drive in his '71 Nova.
This shows the depth difference between a truck balancer on the left and a Camaro/Firebird balancer on the right.
Kunkel sent us this photo of an F-car accessory drive on his iron 6.0L engine. Because his Hooker engine mounting plates
move the engine back farther than most to fit the LS1 swap headers, he had to notch the crossmember to fit the
alternator. He has already reinforced and filled in this notch to make it stronger and look better. With most engine
mounts, the F-car drive alternator clears the stock subframe.
We mocked up an iron 6.0L engine using Scoggin-Dickey engine mounts and a truck accessory drive on a '66 Chevelle
and found that a 6-inch power steering pulley hits the power steering box. This can be rectified with a smaller, GM 5inch-diameter pulley (PN 10166335). This smaller pulley has a 0.750-inch shaft diameter.
CC reader Troy Matos sent us this photo of an '04 LQ4 6.0L engine in his '65 Chevelle. Since his car has manual steering,
he opted for a passenger-side alternator conversion he found online by referencing "Smokinhawk" at LS1tech.com.
We've discovered that the F-car and truck alternators are interchangeable, meaning you can probably find a less
expensive alternator from a truck compared with purchasing one for a Camaro. These alternators will not interchange
with a Corvette system because the mounting lug spacing is different--of course.
This is an exploded shot of the components you get if you step up to one of the GM Performance Parts complete
accessory drive kits. The kits come with everything you need to bolt to the front of a Gen III/IV engine except a harmonic
balancer.
On the right is a factory Type I truck power steering pump. Most all LS passenger car-type accessory drives use the later
Type II pump (left) as installed on a stock F-car accessory drive. The integral plastic reservoir can either be retained or
easily removed so the pump can be modified for a remote reservoir.
This is a Type II pump we purchased from Rock Auto. According to Street & Performance, the casting numbers 783 and
784 use a 0.660-inch shaft diameter and are supported by a sealed bearing.
This factory pulley for Type II pumps with a 0.660-inch shaft diameter has windows that allow access to the pump
mounting bolts. This means you don't have to remove the pulley to install or remove the pump.
This Kwik Performance kit mounts the alternator up high much like a factory Y-car system, placing the power steering
pump high enough on the driver side to clear the steering box and upper control arms on most applications. We
assembled this entire accessory drive package using a Bosch truck alternator, an A1 Cardone power steering pump, and
a Gates serpentine belt from Rock Auto.
Kwik also offers a separate A/C mount kit for aftermarket Sanden compressors that places the unit high on the
passenger side of the engine for maximum clearance, using one belt to run all the accessories.
This bracket kit is less than $200.00, but you supply the compressor.
The alternator we used is an internal fan model CS130D.
Painless makes a pig-tail conversion (PN 30705) using the GM connector to adapt the alternator to your charging system
harness. If the alternator has an external fan, the Painless pig-tail PN would be 30707.