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1991 GMC Syclone Hummer Starter Motor (Proform) NEW

$ 223 .89

Product Notes

High-Torque Starter; Gear Reduction Type; 1.4KW; Compression Ratio:11 : 1; Finish:Natural; Flywheel Tooth Number:153 and 168-Tooth; Gear Reduction Ratio:3.75:1; Material:Aluminum/Steel; Mounting Plate:Straight Bolt Mounting Plate

High-torque, gear-reduction design. 100% NEW, not rebuilt. Offset design results in more clearance between the oil pan and the starter, and can be rotated for additional chassis clearance. The high-torque, high-output motor spins the engine over faster than stock starters, delivering 40-50% more cranking power. 3.75-to-1 sealed gear-reduction drive and full ball bearing construction. Includes shims to set pinion-gear engagement (when necessary). Approved by all leading sanctioning organizations. Fits all Chevy V6 and small and big block V 8 engines using 153 or 168 tooth flywheels. Heavy-duty PROFORM P/N 66258 weighs 1-1/2 lbs. more and is 1" longer than P/N 66256.
Brand: Proform
Condition: New
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TIME
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Specifications & Info


Attribute Value
Applications Chevy Small Block Engines, Chevy Big Block Engines And Chevy V6 Engines
Category Starters
Compression Ratio 11 : 1
Family Mini Hitachi
Feature/Benefit High-torque, Gear-reduction Design.
Finish Natural
Flywheel Tooth Number 153 & 168-tooth
Gear Reduction Ratio 11.0:1, 3.75:1
Grade Type Performance
Make Chevrolet
Material Aluminum/steel
Mounting Plate Straight Bolt Mounting Plate
Mounting Type Flange
Nose Cone Type Open Nose
Power Output 1.4 Kw
Rotation Standard
Solenoid Attached Yes

Vehicle Fitment Guide

This part fits the following vehicles:

GMC 1 model (tapclick to expand)(tapclick to hide)
Syclone 1991 (tapclick to expand)(tapclick to hide)
Swipe left/right to see more info
SubmodelSUB-
MODEL
Body Style Years Engine Attributes
Base Standard Cab Pickup 1991 V6 4.3L Turbo AWD Automatic
Verify before ordering — please confirm your vehicle's year, make, model and sub-model specifications before placing your order. If anything is unclear, our customer service team is available to help.

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Shipping Information

We offer fast, reliable shipping on all orders:

  • Ships to all countries via US Postal Service Priority Mail.
  • Most orders ship within 1 business day.
  • Delivery time: 1-4 business days after shipment.
  • International shipping available, including APO/FPO addresses.
  • Tracking information provided for all shipments.
  • Additional handling fees may apply for oversized/overweight packages.

Return Policy

We want you to be 100% satisfied with your purchase. That's why we offer:

  • 120-Day Returns - Return any part within 120 days from date of receipt.
  • Must obtain RMA (Return Merchandise Authorization) number before returning.
  • Parts must be in original condition, uninstalled, unaltered, and in original packaging.
  • Important: Electrical parts are not returnable if unsealed.
  • Please inspect parts upon arrival and notify us within 5 days of receiving incorrect or damaged parts.
  • Refunds processed after warehouse receives return and credited to original payment method.

Warranty

This part comes with a limited lifetime warranty. Warranty begins on the original purchase date.

Warranty does NOT cover:

  • Shipping costs or labor expenses.
  • Installation errors.
  • Parts used for racing.
  • Commercial vehicle parts.
High-torque, gear-reduction design. 100% NEW, not rebuilt. Offset design results in more clearance between the oil pan and the starter, and can be rotated for additional chassis clearance. The high-torque, high-output motor spins the engine over faster than stock starters, delivering 40-50% more cranking power. 3.75-to-1 sealed gear-reduction drive and full ball bearing construction. Includes shims to set pinion-gear engagement (when necessary). Approved by all leading sanctioning organizations. Fits all Chevy V6 and small and big block V 8 engines using 153 or 168 tooth flywheels. Heavy-duty PROFORM P/N 66258 weighs 1-1/2 lbs. more and is 1" longer than P/N 66256.

Fits Years: 1991

Fits Models: Syclone

Go-Parts Garage · Featured Guide

GMC Syclone Starter Motor: A Guide to Solving Starting Issues

Don't get stranded—understand the common starter problems and upgrade options for your 1991 Syclone.

Read Full Guide

⚠️ Related Trouble Codes (OBD-II)

1 matching guide

If your scan tool is showing one of these trouble codes, this part is a common fix. Each guide explains the code, how to diagnose it, and exactly what to replace.

↑ A single part can trigger multiple related trouble codes. Each guide is vehicle- and code-specific.
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