Technical Information on Rebuilding GM LS Engines - Engine Builder Magazine

Technical Information on Rebuilding GM LS Engines

The Issue: When the OE composite designed cylinder head gasket changed to an improved Multi-Layered Steel (MLS) design for the 4.8L & 5.3L in 2001 and 6.0L in 2002, the cylinder head gaskets were no longer interchangeable. This prevents engine builders and technicians from installing the best MLS designs in older engines of the GM LS series due to resulting coolant leaks.

The Resolution: Through vigorous testing and analysis, Victor Reinz has engineered a replacement MLS gasket design that fits GM Gen III 4.8L, 5.3L (1999-2000) and 6.0L (1999-2001) series engines. These gaskets accommodate both the early and late style head design. Additionally, the MLS design features an embossed stainless steel stopper layer.

Victor Reinz utilizes state-of-the-art Intellicoat™ blue FKM elastomer coating on the “active” layers. This special coating is recognized for the outstanding ability to seal the head and block mating surfaces (up to 60RA) without the need for exotic surfacing equipment and techniques.

The Application: GM LS series Gen III and IV, 4.8L, 5.3L, 5.7L, 6.0L and 7.0L from 1999 thru 2009 are covered with these four new part numbers:

54441 – GM 4.8L VIN V, 5.3L VIN P, T & Z 1999-2007

54442 – GM 4.8L VIN C 2007-2008, 5.3L All VIN except P, T & Z 2005-2009, 5.7L 1997-2005

54445 – GM 6.0L VIN H, N & U 1999-2008

54446 – GM 7.0L 2006-2008

Consult your Victor Reinz Gasket Catalog or your local distributor for exact application/part number detail.

This Solution, as well as other gasket, engine bearing, piston ring and heavy duty solutions can be found on

You May Also Like

Shop Solutions January 2023

Next time you have set of large journal small block Chevy connecting rods to resize, consider honing the big ends of them for a +.002” outside diameter bearing that the LS engines with fracture cap rods use.

Engine and Machine Shop Tips and Tricks


For proper block cleaning, the oil bypass valves in Gen 5 and 6 big block Chevys need to be removed. We made a couple different sized “hook” tools for a slide hammer. This tool will easily pull the valves out of the block and sometimes without damaging them.

Shop Solutions December 2022

Everyone misses occasionally, and this helps avoid dents and damage.

Jesel Certified Performance Rebuilds

Engine components are serious investments for any racer and maintaining that investment could be the difference between winning a championship and losing it.

Going the Extra Mile with Cylinder Head Porting

It’s not just the port work alone that creates spectacular cylinder head performance. The most critical areas of a cylinder head are those which pass the most air at the highest speed and for the longest duration. Your bowl area, the valve job, the throat diameter, and combustion chamber are all crucial parts. 

Tight Tolerances and Building Power

As you ascend Mt. Everest, you reach an area called the death zone. Once you climb high enough, the margin of error becomes perilously thin. That death zone also applies to engines. As the horsepower per cubic inch and rpm increase, the margin of error decreases. 

Other Posts

CNC Update: Features and Automation

Precision is key when it comes to automotive parts; the complex designs of connecting rods, pistons and rings, blocks, cylinder heads, and other parts require super tight tolerances that are getting more and more difficult to be met by hand or with other machining processes outside of CNC.

All Things Media Blasting

Engine building is a segment of the automotive industry that has always been ahead of the curve in media blasting, and no matter the engine shop, cleaning equipment is a common bond.

Engine & Hub Dynos: Necessary Tools and Additional Revenue

Being able to see the horsepower and the direct correlation to what is lost in the driveline is invaluable – dynos offer a myriad of benefits for the modern engine shop.

November 2022 Shop Solutions

November tricks and tips for the shop!