Pro Underdrive Kit With 6" Water Pump Pulley 20R/22R/RE/RET
Street Underdrive Kit(6") - 20R/22R/RE/RET
Our Price: $199.95

Part Number: 1016120

Crankshaft Pulley*:

Details Fitment

Pro Underdrive Kit

(6" Water Pump Pulley)

Street vehicles running high RPM engines often overdrive the water pump making the engine's cooling system inefficient. These Crankshaft Power Pulleys reduce water pump and alternator RPM providing better cooling and less power loss. The lightweight of these billet aluminum pulleys will reduce the drag on your engine, while the underdrive design will allow your engine to turn your front belt accessories with less effort. All this means you gain performance and a cleaner looking engine compartment.

Each 4" diameter Crankshaft Power Pulley is made from 6061 T-6 aluminum and is then hard anodized for extra wear resistance. Another added benefit is the built-in degree wheel on the front of the pulley that will allow you to dial in your top dead center point much more accurately. Our Underdrive Kit for street applications includes a 6" polished billet water pump pulley, 4" crank underdrive pulley (your choice of single, dual, or triple, depending on your needs see below), adjustable timing tag, front balancer bolt, and belt for street applications running an alternator.

There are (3) pulleys to choose from:

  • Single groove would be a race application only, running an alternator with no power steering or other belt-driven accessories.
  • Double groove would be used with an alternator and A/C or custom belt accessory and no power steering.
  • Triple groove pulley would be used for running alternator A/C and power steering

The stock belt orientation is as follows:

  • Inner Belt: Water pump / Alternator
  • Middle: A/C
  • Outermost: Power Steering

NOTE: Not recommended for stop and go driving or for 4wd vehicles in general. This is for street strip vehicles maintaining high rpm. For high RPM full race applications, see Part #: 1016123 and Part #: 1016124. You may need to swap the tensioner bolt for power steering to a rounded cap head bolt for belt clearance.

This product should not be used in a manner that violates Federal EPA Laws.

Contact our Tech Support Line for further information at 928-855-6341.

Check out for New Products, Tech Articles, Specials & Monthly Newsletters!

Note: Images are for illustration purposes only. Images may not represent the product listed. Please contact customer service with any questions or concerns: 1-928-505-2501.

Average Customer Review: Average Customer Review: 5 of 5 5 of 5 Total Reviews: 8 Write a review.

  0 of 0 people found the following review helpful:
5 of 5 January 5, 2022
Reviewer: Anthony cm Quenga from Las Vegas, NV United States  
Truck runs good and has fast response. Shipping is fast. Brian is a great salesman and recommends what’s good for your vehicle.

Was this review helpful to you?

  0 of 0 people found the following review helpful:
5 of 5 Part October 22, 2020
Reviewer: Justin C Ayuyu from Bellevue, WA United States  

Was this review helpful to you?

  0 of 0 people found the following review helpful:
5 of 5 Oval track October 22, 2020
Reviewer: B. from Wa  
I'm excited to use it but I haven't been able to put it on yet but it did show up within a week but I'm excited

Was this review helpful to you?

  2 of 2 people found the following review helpful:
5 of 5 Great pulley, more response September 11, 2018
Reviewer: SAUL GARAY from Las Vegas, NV United States  
Swapped the crank and fan pulley. They look great and i found the powersteering belt at AutoZone 13A1065 Duralast brand. Its a snug fit over the pulley but it tightens up well with tensioners.

Was this review helpful to you?

  0 of 0 people found the following review helpful:
5 of 5 . April 27, 2018
Reviewer: Zhivago Luis from Castle Rock , CO United States  

Was this review helpful to you?

View All Customer Reviews