General Motors - Auto Specialties Performance - Quality Performance Products

Get Up To “15” Extra Horsepower In 30 Minutes!
You’ll also get better fuel milage and increased accessory life!

What do Underdrive Pulleys do? Underdrive pulley systems increase engine horsepower by reducing the amount of power required to drive external engine accessories. For example, the alternator, power steering, water pump and air compressor rob horsepower from the engine. By replacing factory-sized crank and accessory drive pulleys with a resized pulley, the accessories are slowed, resulting in more horsepower available to the drive wheels. Typically, a set of Auto Specialties street pulleys will increase horsepower by 12-15, and increase mileage by 2 to 3 MPG. All pulleys are manufactured from Billet Steel or Aluminum, exceeding factory quality.

1998-02 LS1 25% Harmonic Dampner Crank, 15% Alt. Pulley Kit

ASP LS1 underdrive pulley kit reduces parasitic power losses associated with high accessory speeds, freeing up additional HP. It also reduces the rotating inertia on the front of the crankshaft allowing for faster revving. We have seen just over 13 rear wheel hp increase with this kit installed on stock LS1s.

NEW 2010 Camaro Pulley Kit (p/n# 541430)

Camaro / Firebird / Cadillac

Camaro / Firebird Street Pulleys
Black Nitride (Serpentine) .20
+ Second Quarter-Mile Gain
Part # ASP540801

Nitride Overdrive Alternator Pulley

“LT-1” 2 pulley Kit
“LT-1” 34% Add-On Crank Pulley 15% Alternator, .1 to .15 Second Quarter-Mile Gain
Part # ASP847601

Year

Engine

Pulley Description

Full Charge

Info

Image

Nitride

Hard Coat Black Alum

2010-14

LS3/L99

15% Harmonic Dampner Crank

800 RPM

–

ASP541430
$235.00

— N/A —

98-02

LS1 350

25% Harmonic Dampner Crank

800 RPM

ASP948500
$265.00

— N/A —

98-02

LS1 350

25% Harmonic Dampner Crank
15% Alternator

950 RPM

–

ASP948584
$275.00

— N/A —

93-97

LT1 350

34% Crank

950 RPM

–

— N/A —

ASP847600
$89.95

93-97

LT1 350

34% Crank
15% Alternator

1050 RPM

–

— N/A —

ASP847601
$109.95

93-97

LT1 350

23% Crank

800 RPM

ASP945100
$165.00

— N/A —

93-97

LT1 350

23% Crank
15% Alternator

900 RPM

–

ASP945103
$185.00

— N/A —

82-95

305, 350

25% Crank

800 RPM

ASP540800
$94.00

— N/A —

88-92

305, 350

25% Crank
23% Alternator

950 RPM

–

ASP540801
$101.95

— N/A —

88-95

2.8, 3.1, 3.4

25% Crank

900 RPM

ASP541800
$74.95

— N/A —

88-95

2.8, 3.1, 3.4

25% Crank
23% Alternator

1100 RPM

–

ASP541801
$94.95

— N/A —

85-87

305, 350

25% Crank

750 RPM

ASP541100
$82.95

85-87

305, 350

25% Crank
23% Alternator

1000 RPM

ASP541101
$102.95

82-85

305, 350
(3V-Groove)

25% Crank

750 RPM

ASP541300
$88.95

ASP841300
$125.00

82-85

305, 350
(3V-Groove)

25% Crank
12% Alternator

950 RPM

ASP541302
$109.95

ASP841302
$145.00

Cavalier

Year	Engine	Pulley Description	Full Charge	Info	Image	Clear Coat Alum
96-00	2.4L Cavalier	25% Crank	— N/A —	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. Loosen front passenger side lug nuts. 2. Place blocks behind rear wheels to prevent car from rolling back. Jack up passenger side of vehicle and support with jack stand. 3. Remove the front passenger side wheel and wheel well shroud. 4. Loosen crankshaft pulley bolt (bolt is very tight). 5. Remove factory belt. 6. Remove crankshaft pulley bolt and crankshaft pulley. 7. Install the underdrive pulley with multi-purpose grease or oil on the inner bore. 8. Torque crankshaft pulley to 159 ft/lbs. 9. Install new belt Gates K050455 10. Tighten belt to factory specifications. 11. Reinstall passenger side wheel shroud and front wheel. 12. Remove jack stand and lower vehicle. 13. Turn on vehicle and inspect for any pulley wobble and that belt is properly seated in all pulleys.		ASP840096 $124.95

Corvette / Cadillac CTS-V

Year	Engine	Pulley Description	Full Charge	Info	Image	Nitride	Hard Coat Black Alum
04	350 LS1	Cadillac CTSV NA	900 RPM	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. Disconnect the negative battery cable and remove both serpentine belts. Use a 15mm wrench to rotate the tensioner clockwise, releasing tension. 2. Remove power steering rack. Drain fluid first. Remove the intermediate shaft shield. Disconnect the pump inlet hose from the rack. See fig. 1 & 2 3. Disconnect the power steering cooler from the rack and remove from car. See fig. 3 4. Disconnect the lower steering coupling from the rack. See fig. 4 5. Raise and support the car. Remove the right and left front tires. 6. Disconnect both outer tie rods from the steering knuckles. Disconnect the electrical connector for Magnasteer. 7. Remove the front stabalizer bar from the vehicle and remove the steering rack mounting nuts and bolts. See fig. 5 8. Remove rack through the left wheelwell opening. See fig 6 9. Remove factory crank pulley by removing single dampner bolt. Standard clockwise thread. 15/16 socket. 10. Use 3 jaw puller to remove factory dampner. Attach to tabs on pulley. See fig. 7 11. Clean crank shaft and install new underdrive pulley. NO orientation is necessary. Apply grease UNDER the bolt washer or bearing on balancer installation tool, to reduce friction between the alum hub and tool. 12. Once pulley is seated use the factory bolt to tighten the pulley to final location. Tighten to 240 lb/ft. Tighten the bolt a second pass to 120 degrees using an angle torque gauge. Remove bolt if have a new one. 13. If have new bolt, install now with red loctite applied to threads. 14. Torque to 37lb/ft. Tighten to 120 degrees using an angle torque gauge. 15. Install the new belts. 16. Reinstall the power steering rack / cooler in reverse order. 17. Bleed rack system by turning wheek lock to lock at least 20 times. Checking for correct fluid level. Do this while wheels are off the ground and engine off. 18. Reconnect battery cable. Start car and check for any leaks and proper belt alignment. Drive and recheck the power steering fluid level. BELTS Gates K040410 A/C Gates K060775 TORQUE SPECS. Steering rack mounting nuts = 74 lb/ft. Intermediate Shaft clamp = 32 lb/ft. Tie rod end nuts = 33 lb/ft. Power steering cooler fitting and inlet hose = 20 lb/ft. Intermediate Shaft clamp = 32 lb/ft		ASP941020 $248.00	— N/A —
97-09	350 LS1/ LS2 / LS3	25% Harmonic Dampner Crank 10% A/C Reduction	850 RPM			ASP941020** $248.95	— N/A —
93-96	350 LT1	22% Crank	800 RPM			ASP945800* $165.00	— N/A —
93-96	350 LT1	22% Crank 15% Alternator	900 RPM			ASP945803* $185.00	— N/A —
84-91	350	22% Crank	750 RPM	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. Remove existing belt and pulleys. Remove spacer ring from behind factory alternator pulley. 2. Install new pulley. Use Loctite Thread Lock #242, or equivalent, to secure bolts. 3. For 84-87 install Gates belt K060860 w/crank, Goodyear 4060865 w/crank & alternator pulley (K060860 for 84); for 88-91 install Gates K060900 w/crank, Gates K060905 w/crank &alternator pulley. 4. Insure adjustments marks on tensioner are within the limit marks.		ASP540200 $82.95	— N/A —
84-91	350	22% Crank 23% Alternator	950 RPM	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. Remove existing belt and pulleys. Remove spacer ring from behind factory alternator pulley. 2. Install new pulley. Use Loctite Thread Lock #242, or equivalent, to secure bolts. 3. For 84-87 install Gates belt K060860 w/crank, Goodyear 4060865 w/crank & alternator pulley (K060860 for 84); for 88-91 install Gates K060900 w/crank, Gates K060905 w/crank &alternator pulley. 4. Insure adjustments marks on tensioner are within the limit marks.		ASP540201 $105.00	— N/A —
88-91	350	22% Crank 23% Water Pump	750 RPM	–		ASP540220 $125.95	— N/A —
88-91	350	22% Crank 23% Alternator 23% Water Pump	950 RPM	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. Loosen alternator nut and four water pump bolts. 2. Remove inlet air tube from intake scoop to allow wrench handle clearance when installed in tensioner. 3. Relax tension from belt and remove belt from alternator pulley. 4. Remove alternator pulley and spacer ring and four water pump pulley bolts. 5. With vibration dampner and water pump pulley removed, remove four crank pulley bolts with standard deep socket. Remove crank pulley by working up past water pump. (Optl: Loosen 15 mm tensioner bolt and swing tensioner up for easier removal.) 6. Remove upper alternator mounting bolt. Loosen lower bolt and alternator brace bolts. 7. Install alternator bracket: (a) swing alternator out approximately 3/4″. (b) Place bracket on rear side of alternator. Install original bolt through bracket and into cast anchor brace from rear. (c) Place spacer in position on rear side of alternator anchor lug and install 5/16 x 2.00 bolt into bracket, spacer and lug. (d) Tighten all bolts and nuts. 8. Install crank pulley and tighten with socket wrench. (Use Loctite Tread Lock #3242 on all threads.) 9. Place belt under crank pulley and in position under water pump pulley. Install water pump pulley and vibration dampner. 10. Position belt in all grooves. Place alternator pulley under belt in grooves. Slide alternator pulley onto alternator shaft while holding tensioner down in loose belt position. (This allows for easy belt installation.) Install alternator nut and toghten. 11. Insure tensioner marks are within their specified limits.		ASP540221 $155.95	— N/A —
75-82	350	28% Crank	800 RPM	–		ASP542100 $125.00	ASP842100 $125.95
75-82	350	28% Crank 12% Alternator	1000 RPM	–		ASP542102 $145.00	ASP842102 $145.95
71-74	350	25% Crank	800 RPM	–		ASP543400 $224.00	ASP843400 $125.95
71-74	350	25% Crank 12% Alternator	900 RPM	–	–	ASP543402 $145.00	ASP843402 $145.95

* Will not work with LT-4
** Will not work on Z06

Pontiac

Year	Engine	Pulley Description	Full Charge	Info	Image	Nitride	Hard Coat Black Alum
09-11	LS2	–	— N/A —	–	–	ASP540025 $248.00	— N/A —
98-04	GTP Eaton 90SuperCharged	3.25″ +6 lbs of Boost, Requires #003435	— N/A —	–		ASP540032 $99.95	— N/A —
98-04	GTP Eaton 90SuperCharged	3.40″ +4 lbs of Boost, Requires #003435	— N/A —	–		ASP540034 $99.95	— N/A —
98-04	GTP Eaton 90SuperCharged	3.50″ +2 lbs of Boost, Requires #003435	— N/A —	–		ASP540035 $99.95	— N/A —
98-04	Pontiac GTP Pulley Puller	Required for 540034 & 540035		Auto Specialties recommends that these pulleys be installed by a qualified mechanic. ASP recommends that pulley installation and removal be done by qualified technicians only. This tool is intended for experienced service technicians only. LIST OF CONTENTS (1) Aluminum pulley removal plate (1) Aluminum square brace (1) Threaded shaft 5/8- 11 (1) 5/8-11 G5 nut (1) 5/8 flat washer (2) 3/8 flat washer (2) 3/8 -16×5 alloy SHCS Allen bolts (1) 5/16 flat washer (1) Handle (1) Piece of belt TOOLS NEEDED Vice grips 15/16 wrench 1/2 socket 10mm socket 21mm wrench 15mm wrench for tensioner Never seize or grease for threads on thread bolt Dikes PULLEY REMOVAL 1. Remove fender brace with 13mm socket 3 bolts. On 97 the water bottle will have to be removed under the brace. 2. Remove bottle using dikes or flat tip screwdriver. On 98 and newer there is no bottle. 3. If your car is a 1997, disconnect the 2 electrical connectors, one on top and one on bottom of bottle, and remove the nut holding the washer bottle. Lift bottle out and place drain hose over disconnected waterline on bottom. This will prevent any water leaks. 4. Remove fuse box by removal of 1/2 nut on strut tower. DO NOT disconnect any electrical connections, not necessary. Lift up and forward as there is a lip on the bottom of box that is inserted into the strut tower. This box will move forward enough to give working room. On some cars the main wiring harness is secured by a metal clip that must be opened in order to move forward. 5. Remove bolt in center of pulley using 21mm wrench. 6. Loosen belt with 15mm wrench and remove belt. Pull tensioner toward the radiator. 7. Set up pulley removal tool as displayed in . 8. Important: grease must be applied to threads to prevent gauling. 9. Tighten 3/16 bolts to get even distrubution of tension on pulley plate. 5/8 shaft must be screwed in to the blower snout with 5/16 washer on end. Tighten with 15/16 wrench. 10. Begin removal by turning 5/8 nut counter clockwise, this will pull the pulley off. Pulley Installation 1. Use only the 5/8 bolt and the square brace with 5/8 washer and nut. 2. Optional: may need. Place belt piece supplied around pulley and tighten with vice grips. This will keep the pulley from spinning as you tighten the pulley on. 3. Tighten the shaft onto the blower snout with square brace on pulley face. 4. Begin tighten the nut. 5. Keep 5/8 shaft from trying to tighten up by holding wrench to keep shaft from turning. If shaft tightens as pulley is pressed on, it WILL BREAK the stud in the blower shaft. 6. When pulley stops, disassemble and remove 5/16 washer. 7. With washer removed repeat as before until pulley stops. The pulley should be flush with the blower shaft. 8. Replace belt and nut on end of shaft. 9. Reverse disassembly of water bottle if applicable and fuse box. Make sure box is inserted into the slot on the strut tower. 10. Replace fender brace. NOTE: Make sure car is cooled down as heat will swell the shaft making difficult. Ther is no guarantee the stock pulley will be removed without damage. If you have any questions, or reservations about doing the install, do not attempt without help. ASP is not responsible for damage due to incorrect installation or removal.		ASP003435GT $130.00
91-96	3.4L Pontiac Grand Prix	20% Crank	— N/A —	Auto Specialties recommends that these pulleys be installed by a qualified mechanic. 1. REMOVE EXISTING BELT AND CRANKSHAFT PULLEY. 2. INSTALL NEW PULLEY. USE LOCTITE THREAD LOC #242, OR EQUIVALENT TO SECURE BOLTS. 3. INSTALL DAYCO BELT #5060715. 4. INSURE ADJUSTMENT MARKS ON TENSIONER ARE WITHIN THE LIMIT MARKS. 5. ONCE CAR IS CRANKED UP, INSPECT FOR PULLEY WOBBLE AND THAT BELT IS PROPERLY SEATED IN PULEYS.		— N/A —	ASP840104 $124.95
91-96	3.4L Z – 34 *	20% Crank	— N/A —			— N/A —	ASP840104 $124.95
96-00	2.4L Pontiac Sunfire	25% Crank	— N/A —			— N/A —	ASP840096 $124.95

* Requires spacer

Fiero

Year

Engine

Pulley Description

Full Charge

Info

Image

Hard Coat Black Alum

85-88

2.8

25% Crank

900 RPM

ASP845200
Call

85-88

2.8

25% Crank
23% Alternator

1100 RPM

ASP845202
Call

Trucks

Year

Engine

Pulley Description

Full Charge

Info

Image

Nitride

Hard Coat Black Alum

2014

L83

23% Harmonic Dampner

850 RPM

–

ASP541460
$285.00

— N/A —

99-13

4.8, 5.3, 6.0, 6.2

25% Harmonic Dampner

800 RPM

ASP549900
$255.00

— N/A —

99-10 *

4.8, 5.3, 6.0, 6.2

25% Harmonic Dampner
23% Alternator

950 RPM

ASP549984
$275.00

— N/A —

08-10

4.8, 5.3, 6.0, 6.2

25% Harmonic Dampner
23% Alternator

950 RPM

ASP549984
$275.00

— N/A —

99-04

4.8, 5.3, 6.0

25% Harmonic Dampner –
Overdrive Alternator

950 RPM

–

ASP549920
$275.00

— N/A —

08-10

4.8, 5.3, 6.0

25% Harmonic Dampner –
Overdrive Alternator

950 RPM

–

ASP549920
$275.00

— N/A —

94-98

454

25% Crank

750 RPM

— N/A —

ASP846200
$92.50

94-96

454

25% Crank
23% Alternator

950 RPM

— N/A —

ASP846201
$119.10

97-02

454

25% Crank
23% Alternator

950 RPM

— N/A —

ASP846284
$119.10

88-93

454

25% Crank

750 RPM

ASP543800
$105.00

— N/A —

88-93

454

25% Crank
23% Alternator

950 RPM

ASP543801
$120.00

— N/A —

82-88

6.2 Diesel

25% Crank

950 RPM

–

ASP541200*
$150.00

— N/A —

88-98

4.3, 305, 350

25% Crank

750 RPM

ASP541000
$84.95

ASP841000
$89.95

88-06

4.3

25% Crank

750 RPM

ASP541000
$84.95

ASP841000
$89.95

97-02

350

23% Alternator

750 RPM

ASP541084
$101.95

— N/A —

88-96

4.3, 305, 350

25% Crank
23% Alternator

950 RPM

ASP541001
$105.00

ASP841001
$109.95

88-95

4.3, 305, 350

25% Crank
23% Alternator
14% Water Pump

950 RPM

ASP541051
$170.00

ASP841051
$175.00

85-87

454

25% Crank

750 RPM

–

ASP540900
$150.00

— N/A —

85-87

305, 350

25% Crank

750 RPM

ASP541100
$82.95

85-87

305, 350

25% Crank
23% Alternator

1000 RPM

ASP541101
$102.95

81-84

305, 350

25% Crank

750 RPM

ASP541300
$88.95

ASP841300
$125.00

81-84

305, 350

25% Crank
12% Alternator

950 RPM

ASP541302
$109.95

ASP841302
$145.00

87-95

2.8

25% Crank

850 RPM

ASP541800
$74.95

— N/A —

87-95

2.8

25% Crank
23% Alternator

1100 RPM

ASP541801
$94.95

— N/A —

85-86

2.8

25% Crank
IV-4 rib sup.

850 RPM

–

ASP546700*
$100.00

— N/A —

85-86

2.8

25% Crank
23% Alternator

950 RPM

–

ASP546702*
$125.00

— N/A —

94-03

2.2L L-4, S-10

20% Reduction Crank Pulley

850 RPM

–

ASP840127
$89.95

Early Model Crank Pulleys

Year	Engine	Pulley Description	Full Charge	Info	Image	Black
69-84	Chevy Sm. Blockwith Long Water Pump	25% Crank 1-Groove	— N/A —	–	–	ASP947100* $89.95
— N/A —	— N/A —	2-Groove	— N/A —	–	–	ASP947200* $125.00
55-68	Chevy Sm. Blockwith Long Water Pump	25% Crank 1-Groove	— N/A —	–	–	ASP948300* $249.00
— N/A —	— N/A —	2-Groove	— N/A —	–	–	ASP948100* $145.00
— N/A —	— N/A —	3-Groove	— N/A —	–	–	ASP948200* $145.00
69-78	Chevy Sm. Blockwith Long Water Pump	25% Crank 3-Groove	— N/A —	–	–	ASP947800* $125.00
69-79	389, 400, 428,455 Pontiac	28% Crank	750 RPM	–		ASP942000* $125.00
69-79	389, 400, 428,455 Pontiac	28% Crank 12% Alternator	1000 RPM	–	–	ASP942002* $145.00

Alternator Pulleys

Nitride Overdrive Alternator Pulley
For Serpentine Belt Systems
– 32% overdrive alternator pulley
– Increased charging capacity
– CNC -machined billet nitride
– 1997-2002 also avaliable

Year	Engine	Pulley Description	Info	Image	Nitride	Hard CoatBlack Alum	Black
97-02	All Engines	1 3/4″ Overdrive Alternator	–		ASP540120 $38.00	— N/A —	— N/A —
97-02	4.3, 305,350, 454	2 3/4″ Alternator	–		ASP540084 $39.00	— N/A —	— N/A —
84-96	4.3, 305,350, 454	2 3/4″ Alternator	–		ASP540001 $38.00	ASP840001 $26.95	— N/A —
84-96	4.3, 305,350, 454	1 3/4″ Overdrive Alternator	–		ASP520004 $32.00	— N/A —	— N/A —
— N/A —	Early Model	3″ Single Groove	–		— N/A —	ASP840002 $45.00	— N/A —
— N/A —	Early Model	3″ Double Groove	–	–	— N/A —	— N/A —	ASP940007* $85.00
— N/A —	Early Model	5″ Single Groove	–	–	— N/A —	ASP840008 $32.95	— N/A —