Are there any disadvantages to dumping the exhaust past the muffler (4.7L and Flowmaster 40 series). It's a common practice on older trucks, but I don't know about newer models. I would love to get rid of the single tailpipe.

 

On an older Ford truck, an exhaust that exited just behind the cab shook the whole truck. It WILL be noisier.

 

The restrictive, soon to rot Flowmaster is the first problem.

It will usually have a lot of annoying resonance in the cab. Especially in the 1800 to 2000rpm range.

 

I was very disappointed to see my 7-month-old Flowmaster 40 is already badly rusting. I cut the exhaust off last night at the rear axle and I love the sound. It sounds like a REAL truck; call me a redneck. I ordered a Magnaflow pro-series cat back that dumps before the rear axle and should be here soon.

 

Magnaflow is a wise choice. They flow very well and will last a very long time.