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Select your vehicle
Vehicle Info Required to Guarantee FitAdd Vehicle

AC Delco®
21649 Plastic Tank GM Original Equipment Series Radiator

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$583.59Save: $252.60(43%)
Manufacturer #21649
Vehicle Info Required to Guarantee FitAdd Vehicle


Core Dimensions:
34 x 17.25 x 1.12 in. Core Size
Recommended Use:
OE Replacement
Tank Material:
Plastic Tank
Color Finish:
Factory Finish
Product Fit:
Direct Fit
GM Original Equipment Series
Quantity Sold:
Sold individually
Lifetime AC Delco limited warranty
Prop 65 Warning:

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Vehicle Fitment Information

Vehicle Name
Fitment Information
1999-2002 GMC Sierra 2500
8 Cyl 6.0L
1999-2004 Chevrolet Silverado 2500
8 Cyl 6.0L
1999-2004 Chevrolet Silverado 2500
8 Cyl 6.0L
1999-2004 Chevrolet Silverado 2500
8 Cyl 6.0L
1999-2004 GMC Sierra 2500
8 Cyl 6.0L
Page 1 of 32 | Showing 1 - 5 of 158 results

Product Information


Trust ACDelco's GM Original Equipment radiators to reboot your cooling system with the precise fit and outstanding quality you can always rely on GM to deliver. Established in 1899, ACDelco manufactures original GM parts and premium OE replacement parts for other brands in the automotive aftermarket.

  • Sturdily built for dependable, long-lasting performance
  • GM original equipment ensures part is engineered to precise requirements
  • Made to withstand rust and premature wear
  • Lightweight design offers superior heat-transfer characteristics
Need help?Call our product expert1-866-529-0412
Chat with us
Mondays - Sundays7am - 11pm ET | 4am - 8pm PT
Warranty Policy
Right parts, guaranteed. If you find any defects, let us know within 60 days and we’ll take care of it. Check out our Warranty Policy for more details.
Shipping Policy
We ship fast so you can get on the road that much faster. Check out our Shipping Policy for more details.
Easy Return Policy
We’re only happy if you’re happy. If you’re not entirely satisfied with your order, you may be entitled to a refund. Check out our Return Policy for more details.

Product Q&A

Do I Need A Special Tool For The Cooling Lines &Oil Cooler Lines?Gerald D.Oct 12, 2021
Best Answer:Hello! No, these use standard threaded flare fittings
Mitchell D.STAFFOct 15, 2021
Does this radiator correspond to GM part number 20935856?John W.Apr 18, 2024
Best Answer:Hi John, I'm glad to assist you. No, this is not a replacement for OE number 20935856. I hope this helps, and we thank you for inquiring.
Arnel E.STAFFApr 18, 2024
I need a radiator for my 2003 Silverado SS awd 6.0. Vin#2GCEK19N631327289. I'M HAVING PROBLEMS PICKING THE RIGHT ONE. WHICH AC DELCO IS THE CORRECT RADIATOR?Christopher S.Dec 29, 2023
Best Answer:Hi Christopher, I'm pleased to assist you. I've tried three VIN decoders and still can't decode the VIN; there must be an incorrect character. I suggest calling our parts specialists at 1-866-529-0412 so we can help you look for the right part. Have a nice day.
Grace G.STAFFDec 29, 2023
Will this fit in a 2006 Sierra 1500 6.0?HammerjFeb 07, 2022
Best Answer:Hi Justin, I'm pleased to assist you. Yes, this radiator is guaranteed to fit the 2006 GMC Sierra 1500 SLE, SLT, and Denali 8 Cyl 6.0L. Click on the link below to order at 55% off the regular price today while supplies last. I hope this is helpful. Enjoy shopping at <a href="http://Carparts.com!" target="_blank">Carparts.com!</a> <a href="https://www.carparts.com/radiator/ac-delco/ac21649?can=CPGG4850" target="_blank">https://www.carparts.com/radiator/ac-delco/ac21649?can=CPGG4850</a>
Grace G.STAFFFeb 08, 2022

Customer Reviews

Found what i needed very easily and didn't take long to receive.
Dawn T.
Purchased on Feb 26, 2024
Arrived quickly, fit perfectly, much better price than the local auto parts store. Couldn't ask for more! Note: there is no drain cock like the original had, but that is typical for replacement radiators.
Peter M.
Purchased on Apr 05, 2023
Plastic Tank Gm Original Equipment Series Radiator
Happy with the product , customer service and the time it took to get here.
The first radiator was damaged in shipping. Sad but was replaced in a week. It was exactly what I ordered and a half hour later I was on the road. Thank you, great customer service.
Christopher S.
Purchased on Dec 29, 2023