Overkill has discontinued tuning and products for the LS4 W-Body platform. Thank you to all my customers for the last 8+ years of interest in my LS4 offerings, I will affectionatly remember my decade plus of W-Body ownership and what it brought for my professionally. I wish you success with your LS4 vehicles!

Note that if you have Overkill tuning through Diablosport, Autocal or HP Tuners, I will continue to provide you tuning support!

As a gift to the community, I'll share details on the MAF upgrade I've been selling, dyno tested an easy 6 wheel horsepower gain. It comes from a Pontiac G8 GT/GXP or 2007-08 Tahoe/Silverado 5.3, and can be purchased under GM part number 15900023 for around $75 new. It is literally a larger version of the factory LS4 MAF sensor, which was borrowed from the V6 models rather than given the larger MAF that the V8 trucks would get. The electrical MAF sensor insert is the same as factory, so the electrical plug will plug right in. For tuning, reference a factory file from the above vehicles.

This is an Overkill original find. Please credit Overkill with this information when sharing, it is appreciated!