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Holley Cast Aluminum Timing Chain Cover - 21-152

Holley Cast Aluminum Timing Chain Cover - 21-152

SKU: 21-152
Regular price $82.75 USD
Regular price Sale price $82.75 USD
Sale Sold out


Holley now offers a solution to the plastic OEM timing chain covers on 1996-up Vortec Small Block Chevy engines. Our cast aluminum timing chain covers are an excellent upgrade from the OEM part, offering the superior durability of an aluminum part with improved functionality.

These cast aluminum covers feature timing indicators molded into the body and are available with or without a crank sensor provision to accommodate both carbureted and EFI applications. The covers are available in two finishes; Natural Cast and Satin Black. They are packaged with a high quality gasket and E-coated mounting hardware for added corrosion resistance


  • Designed as an upgrade from the plastic OEM timing chain covers on 1996-up Vortec Small Block Chevy engines - Replaces GM part numbers 10244600, 12523972, 12523973, 12558343, 12562818, & 93800970
  • Excellent upgrade for Chevrolet Performance crate engines that use the plastic timing chain cover
  • Available for EFI (with crank sensor provisions) and carbureted applications (without crank sensor provision)
  • Includes over-molded FKM oil seal, virtually eliminating concerns of the seal spinning out at high temperatures, which is common with other aluminum timing covers
  • Timing indicator cast into the cover – Intended for use with 8” Vortec balancers and other popular 8” aftermarket balancers
  • Accommodates both stock and aftermarket water pumps
  • Includes high quality gasket, corrosion resistant E-coated hardware, and dowel pins
  • Offered in Natural Cast and Satin Black finishes

Fitment Notes:

  • Fits both Small Block Chevy (SBC) & VORTEC series Small Block Chevy applications
  • Mounting holes at the 10 o'clock and 2 o'clock positions are NOT used on VORTEC series engine fitments
  • Supplied Dowel pins are used on VORTEC series engines fitments ONLY, early Small Block Chevy (SBC) have dowel pins installed in the block and will not be used.
Year Make Model Submodel Engine Size
1999 - 2006 Chevrolet Silverado 1500 294/4.8L V8
1999 - 2006 GMC Sierra 1500 294/4.8L V8
1999 - 2006 Chevrolet Silverado 1500 325/5.3L V8
1999 - 2006 GMC Sierra 1500 325/5.3L V8
2000 - 2006 GMC Yukon 294/4.8L V8
2000 - 2006 GMC Yukon 325/5.3L V8
2000 - 2005 Chevrolet Suburban 1500
2001 - 2006 Chevrolet Tahoe
2001 - 2006 GMC Yukon XL 1500 325/5.3L V8
2002 - 2006 Cadillac Escalade
2002 - 2006 Chevrolet Avalanche 1500
2002 - 2006 Cadillac Escalade EXT
2003 - 2007 Chevrolet Express 2500 294/4.8L V8
2003 - 2007 GMC Savana 2500 294/4.8L V8
2003 - 2007 Chevrolet Express 1500 325/5.3L V8
2003 - 2007 GMC Savana 1500 325/5.3L V8
2003 - 2006 Cadillac Escalade ESV
2004 - 2007 GMC Savana 3500 294/4.8L V8
2005 - 2007 Chevrolet Express 3500 294/4.8L V8
2003 - 2005 Chevrolet Express 2500 325/5.3L V8
2003 - 2005 GMC Savana 2500 325/5.3L V8
2003 - 2005 Chevrolet Silverado 1500 364/6L V8
1999 - 2000 Chevrolet Silverado 2500 325/5.3L V8
1999 - 2000 GMC Sierra 2500 325/5.3L V8
2005 - 2006 GMC Sierra 1500 364/6L V8
2000 GMC Yukon XL 1500
2000 Chevrolet Tahoe 294/4.8L V8
2007 Chevrolet Silverado 1500 Classic 294/4.8L V8
2007 GMC Sierra 1500 Classic 294/4.8L V8
2000 Chevrolet Tahoe 325/5.3L V8
2006 Chevrolet Suburban 1500 325/5.3L V8
2007 Chevrolet Silverado 1500 Classic 325/5.3L V8
2007 GMC Sierra 1500 Classic 325/5.3L V8
2007 GMC Sierra 1500 Classic 364/6L V8

Application Small Block Chevy
Brand Holley
Crank Sensor Provision Yes
Emission Code 5
Engine Chevrolet VORTEC V8
Finish Natural
Gaskets Included Yes
Material Aluminum
Mounting Hardware Included Yes
Product Type Timing Chain Cover
Thickness Standard OEM
Warranty Limited 90 Day
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Policies and FAQs

Return Policy

We accept returns on products within 30 days of delivery. Return shipping is the responsibility of the buyer unless we, the seller, are at fault.

Fault reasons include but are not limited to:
  • Buyer was shipped the wrong product
  • Buyer was shipped a damaged product
  • The product page had incorrect fitment and the part does not fit the Buyer's vehicle
The Buyer will not be refunded outbound shipping unless the Seller (Modern Day Muffler & Brake) is at fault.
In cases where the Buyer purchases and ships the return please note that if the Shipper (ex. USPS, FedEx, UPS, etc.) loses the return we will not be able to offer a refund as the Buyer must contact the Shipper and make a claim.
All products must be returned in original condition, meaning that the product must not be damaged, installed, or missing pieces/parts. If the product is not in original condition a deduction will be issued of up to 100% of the purchase price of the product.
Opened boxes, plastic bags, and other packaging are not considered damage (excluding single use items such as, but not limited to, liquids, software, and other components that cannot be reused/resealed).
When we, the seller, are at fault, please Contact Us for a return label, products returned with a shipping label not provided by the seller will not be refunded to the buyer. Please also note that our return labels are issued with the dimensions and weight of the original shipment, if the product is being returned in any box/package besides the original please Contact Us with the dimensions and weight.

Returns must be sent to this address:
Modern Day Muffler & Brake
774 Broad Street
Wadsworth, OH 44281
Products returned directly to a manufacturer or the incorrect address may be issued a deduction or denied a refund entirely.
If a product was delivered outside the 30 day return window or is no longer in original condition please contact us as we may be able to issue a refund in store credit and/or with a deduction. If this is the case please Contact Us as these situations are handled on a case by case basis.
If there are any questions, concerns, or doubts about return eligibility please Contact Us and we would be more than happy to assist you.

This page and policy were last updated: July 14th 2023


This is the line that runs from the front of the vehicle to the rear. On most vehicles it connects to a junction then you will have rear axle lines. On a few cars the intermediate lines will connect to the rear wheels. It is recommended to change the axle lines if you are replacing the intermediate lines.

Our kits include all of the solid metal lines for that section of the vehicle.

We are happy to help! Please help us to help you by going to our return form and filling out the form as best as you can in order to request a return.

  • Modern Day stands by our parts and is happy to accept returns within 30 days of purchase. Parts must be in new condition.
  • If a part arrives damaged, or is defective, Please report it to us immediately. So we can handle it for your promptly.

Yes but you will need to order in advance. All of our items are not stocked at our location. So please place your order online and we will notify you when it is ready for pick up.

Unfortunately we cannot offer single lines outside of kits

Yes, all are covered by the manufacturer's standard warranty. Most warranties cover the cost of parts. Any installation or other fees are non-refundable.

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Orders typically Arrive within 3 to 10 days depending if it is a stocked item or something we have manufactured at time of sale.

Yes please send us a message through our custom orders page.

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Warranty Information

Customer service is our top priority and because we value your time and energy we ask you to visit our Contact Us page and reach out so that we may assist you in finding the correct warranty for your product. Please include your name, the name on the order, the order number, and the SKU of the product to ensure the quickest and most accurate response to your inquiry.

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