Mufflers

[Profcadd]

Hello friends. I'm going crazy searching online for replacement mufflers for my coach. see my profile for make, model etc.
If you have the same workhorse UFO chassis with GM Vortec 8.1 in the rear, I would appreciate your feedback.

[barmcd]

check here

https://www.donaldson.com/content/dam/donaldson/engine-hydraulics-bulk/catalogs/Exhaust/North-America/F110028-ENG/Exhaust-Product-Guide.pdf

[rgatijnet1]

If you do change to a low restriction muffler, you may also want to consider having your ECM re-programmed to take full advantage of it. Anything that changes the exhaust flow will change the way the ECM adjust the other parameters as you drive.

[Profcadd]

Thanks for all your input. I am booked in tomorrow at a large custom performance exhaust/muffler shop.

[Chopperbob]

Mangaflow makes good 3" straight thru mufflers.
They would sound great on a 8.1. I put one on a 454
Vortex and it really made a difference. Ask a muffler
shop to order it. You can't buy direct. Only about $80.
Good luck!
The thing about GM. stock mufflers is that they are very
restrictive.

[crasster]

Will have to be a custom find. Many Oreilly auto stores will have different ones in stock that you can look at as well as online specs.

[Jarlaxle]

Profcadd wrote:
Thank you Jarlaxle. Yes I am an avid DIY'er. This is a good suggestion. However getting the old mufflers off could be a challenge.

Why? Just measure them in place.

[DSDP_Don]

In this day and age of ordering everything online, this is one of the few things that should be done the old fashion way. Typically, your exhaust can be replaced a generic 5 ton truck muffler. As others stated, drive to a muffler shop and they'll knock it out in an hour. I'm definitely a DIY guy, but this is something a muffler shop is better suited to do.

[Profcadd]

Thank you Jarlaxle. Yes I am an avid DIY'er. This is a good suggestion. However getting the old mufflers off could be a challenge.

[Jarlaxle]

If you're a DIY person...with the engine cold, crawl under the coach with a tape measure. You need these dimentions:

Inlet & outlet pipe number and size.
Length
Width
Height
Shape (round, oval, suitcase, etc)

Write that down. Go to a good auto part store, ask to look through their exhaust books. One will be there that fits!

[Jim]

I had no idea where to get the large muffler for my '94 Bounder so one day I just stopped into an independent muffler shop.

They had my old muffler out, and new muffler installed in under an hour.

So, I'd agree with just as rgatijnet1 says, almost any muffler shop can do the job.

[rgatijnet1]

You may have trouble finding a bolt on replacement but almost any large muffler shop should be able to find a suitable replacement.