7.4l exhaust
 

what was GM thinking when they designed this exhaust system. 2.750" duals back to a huge muffler, then 1 single 2.5" tailpipe. WTF? I guess some exhaust work is in my future. No o2 sensors past the cats so I may clean them out too

Re: 7.4l exhaust
 

It was an utterly weak attempt to control emissions and HP. Also note that if built right, the exhaust should work to create a scavenging vacuum effect on the cylinders of the engine. So as the exhaust cools down, the amount of space needed to evacuate that exhaust is not as large. GM kind of blew it.