American Car Craft Corvette Exhaust Filler Panel - NPP+Dual-Mode+Bi-Mode Exhaust Perforated 2005-2013 C6 - Manual (Page 3)

2008 NPP EXHAUST
The first step will be to lie on your back and look up at the exhaust perches. You will
notice that there are two heavy steel pins protruding from each muffler facing the rear of
the car which pierces a rubber grommet, there will be two between the exhaust tips and
two slightly tucked into the corners of the valence on either side of exhaust tips. It is at
these four locations that any and all adjustments can be made. Place the new panel over
the tips and make an assessment of the adjustment that will need to be performed. It will
be very obvious the NPP muffler system seem to low for the panel and we will solve this
but also look at the tips to see if any adjustments may be necessary left to right. Although
not very common it may be necessary to also adjust the side to side positions as well.
Although it is not absolutely necessary and a little messy you can spray these four
grommets with silicone lubricant. This will help you to perform the next step: Using your
fingertips slide the grommets off the four pins being careful not to completely remove the
grommets from the steel bracket that secure them to the car. Once all four grommets have
been detached from the pins you should be able to grab the exhaust tip assembly and
move them an inch or more in any direction up down sideways etc.
The NPP system MUST be adjusted so that the exhaust will sit close to an
inch higher. This will position the system in the same location as the Z06 of previous
years. In order to do this you will need to bend the four muffler pins directly downward
about an inch. If the tips need to be adjusted simply bend the pin in the opposite direction
as needed. For instance if one of the tips seem like it needs to be adjusted slightly too
right bend the pin to the left. This will force the grommet to pull the tip to the desired
position. This can easily be performed by placing a 16mm deep socket with a long style
extension over each of the pins and use the leverage of the assembly to force the pins to
the new position. Once you have made this adjustment to the pins you can now reinstall
the grommets to the pins effectively raising the two mufflers to the newly adjusted
position. Tech Tip: Another helpful thing to ease the removal and reinstallation of the
grommets is to eliminate the weight of the muffler system from the procedure. This can
be done by using a floor jack and a small block of wood to raise the system just enough
to eliminate the weight so as to allow you to slide the grommets on and off more easily.
The two grommets at the outer corners of the valence will be a little trickier due to the
fact that they are tucked a little into the corners so you will need to force the corner of the
valence out of the way as you slip on the grommets. A friend will be very helpful for this