M&W Aluminum [MWA]
http://www.mwalum.com/
Aluminum suspension tubes

MAC [MAC]
http://www.macmidwest.com/
Exhaust headers and related components

Magnaflow Performance Exhaust [MAG]
http://www.magnaflow.com/
Performance exhaust Systems, mufflers and related components

Magnafuel Racing Fuel Systems [MRF]http://www.magnafuel.com/
Racing fuel systems

Mahle Motorsports Inc. [MAH]
http://www.mahle.com/
Racing Pistons

Mallory [MAL]
http://www.malloryperformance.com/
Distributors, tachometers, fuel pumps, and ignition components

Manley Performance Products [MAN]
http://www.manleyperformance.com/
Valves, pistons and connecting rods

March Performance [MPP]
http://www.marchperf.com/
Performance engine pulleys

Mark Williams [MWE]
http://www.markwilliams.com/
Driveline components and axles

Marshall Instruments [MAR]
http://www.marshallinstruments.com/
Performance gauges

McCreary [MCR]
No web site listed
Racing tires

McGard [MCG]
http://www.mcgard.com/
Lug nuts and wheel locks

McLeod Industries Inc. [MCL]
http://www.mcleodind.com/
Bell housings

Mechanix Wear [AXO]
http://www.mechanix.com/
Race crew apparel

Melling/M-Select [MEL]
http://www.melling.com/
Engine oil pumps

MetTec [MTT]
http://www.mettec.com/
Titanium fasteners and hardware

Meziere [MEZ]
http://www.meziere.com/
Billet aluminum water pumps and chassis accessories

Michigan 77 [M77]
www.engineparts.com/p_clevite.asp
Engine Bearings

Mickey Thompson [MIC]
http://www.mickeythompsontires.com/
Truck and auto performance tires, drag slicks

MicroTemp [MIT]
www.microtempusa.com/
Digital infrared thermometers

Milodon [MIL]
http://www.milodon.net/
Oil pans, valves, gear drives, rod bolts, head and main studs

Mittler Brothers Machine [MBM]
http://www.mittlerbros.com/
Shop equipment and specialty tools (special order only)

Monroe [MON]
http://www.monroe.com/
Shocks and struts

Moog Chassis [MOG]
www.federal-mogul.com/en/
Replacement Chassis Components

Mopar Performance [MOP]
http://www.mopar.com/
Performance parts for Mopars

Moroso [MOR]
http://www.moroso.com/
Peformance parts and accessories

Motive Gear [MOT]
http://www.motivegear.com/
Ring and pinion sets

Motive Gear [MOT]
http://www.motivegear.com/
Ring and pinion sets

Motive Products [MTP]
http://www.motiveproducts.com/
Brake bleeder systems

MPD [MPD]
http://www.mpdracing.com/
Sprint car components and racing jacks

Mr. Gasket [MRG]
http://www.mrgasket.com/
Automotive accessories and gaskets

MSD Ignition [MSD]
http://www.msdignition.com/
Performance ignition components

Mudd-Off [MUD]
http://www.energyrelease.com/
Mud Off, mud releasing agent