I lived for over three years with a loud, droning exhaust system on my 2003 7.3L Excursion. When we would go on trips, especially when pulling our trailer, the person sitting in the right rear seat was subjected to a headache inducing ride and the people in the third row couldn't talk to the people in the front seats without yelling.

The first exhaust modifications I did right after purchasing our Excursion involved removing the stock muffler and tailpipe and having two Aero-Turbine 3 1/2" resonators mounted in line and a 4” tailpipe over the axle. It sounded kind of cool from the outside but droned something fierce inside the cabin at 1700-1800 rpm.

I did my research on what manufacturers offered the quietest 4" turbo-back system and was ready to purchase a Walker BTM when a Google search brought up several Dodge related forums that were talking about the Donaldson M090544 truck muffler. It was said to be quiet, straight-thru except for a single baffle, and 4". Oh, and 51" long overall.

I got underneath my truck and measured the space underneath. The length from the end of the stock down pipe to the over axle tail pipe was about 58". I measured the area from the floor to the bottom of the existing mufflers and the open area between the frame rail and the driveshaft. I measured them all again. And again. I was convinced that it could fit so I ordered one.

For the system I purchased the Summit Racing 4" aluminized F-Series turbo back kit. It was on sale for $269.95 so it got to my house for less than $300 with shipping.

Then I received the muffler. In a huge box. I thought to myself that it must be double-packed--the shipping box around the original box--but when I looked on the bottom and saw the distinctive white and light blue label, I began to get worried. My kids looked at the muffler and asked what it was for. They just shook their heads.

So I took the big box from Summit and a ninety degree 4" pipe I bought for a tail pipe turn down and loaded them in the back of the Excursion. I placed the muffler across both middle row seats. The door barely closed.
When I got to the muffler shop I began to explain what I wanted to do. We unpacked the Summit box and I told them that most of the center section and the muffler that came with the kit would be unnecessary and told them how I wanted them to make the tail pipe.

Then I grabbed the muffler. I began to pull it out of the back seat and it just kept coming out. The owner of the shop just shook his head. His father, who never says anything, spoke up and asked me if I thought it was big enough.

I said it was and that they didn't make a bigger one that would fit.

He just shook his head. His son said, "It's not gonna fit."

I explained that I had measured everything several times and that it would be tight, but it would work. Then I left them to work.

It took them about 2 1/2 hours to complete it, but they worked it out. It fit great and sounds good from the outside, but is very quiet inside the cabin. The 7.3L is such a noisy engine that the overwhelming noise you hear now is the engine itself. The turbo whistles more noticeably than before, but there is no resonation from underneath and you can hear very little exhaust noise from inside.

The Summit exhaust kit is the cheapest one out there for our trucks, is aluminized instead of stainless, and not much to look at. The visual quality of some of the other kits I've seen is more appealing, but the Summit kit has decent bends and fit well. Once it was welded together and underneath the truck where no one can see them, the jig marks and rough end cuts didn't matter. I am very happy with both the exhaust kit and the Donaldson muffler on my truck. I wanted the quietest 4" straight-thru turbo-back I could find and I believe I found it.

 

Thanx for the humorous (they just shook their heads ) and informative post.... glad it worked out for you.

And welcome to the forum!!