The exaust is not designed to protrude thru the GFX bezels and a few who did this on the SS's ended up melting the rear fascia/bumper. The factory exhaust needs to be cut back so it fits inside the concave reliefs inside the top and bottom of the bezels. If the tips are not cut and are too close to the bezels they can transfer the heat to the bezel then to the fascia. After the exhaust is cut the supplied double walled GFX tips are pressed on to hide the rough cut. The GFX tips are 4" in diameter and if you look at the pic below you may be able to fit a slightly larger tip but it would have to be aligned properly. My 4" tips are centered in the reliefs and sit aprox 1/4" back from the edge of the relief. Im sure the same basic principle would apply to aftermarket exhausts as well.....just make sure the tips dont touch the bezels and transfer heat.
