GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Stock replacement mufflers ( Anyone using the Cinnabar replacements? )
Stock replacement mufflers [message #309556] Fri, 28 October 2016 12:15 Go to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
My PO put on some shorter body 2.25 offset/offset mufflers. This required an extension inlet pipe on each side. I'm fighting an exhaust leak at the left donut as the pipe is sitting a bit funky. Someone posted about flowmaster 50s but I think they would be too loud on long trips and expensive. Does anyone have road miles on the Cinnabar mufflers to share? Fit and sound and power comments? My manifolds are good, my exhaust pipes and Y are good, long pipes and tailpipe are NOS GM so not interested in headers or rear muffler discussion at this time.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: Stock replacement mufflers [message #309558 is a reply to message #309556] Fri, 28 October 2016 13:50 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
somewhere I a post walker OEM size replacement 18425 bought from summit for like $35 a muffler. I bought in may of 2014. So, probably 5000 miles with no complaints.


if you are fighting that leak, I would think if you replace that extension inlet with a woven flex pipe, that would put less stress on the exhaust doughnuts??



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/

[Updated on: Fri, 28 October 2016 13:52]

Report message to a moderator

Re: [GMCnet] Stock replacement mufflers [message #309560 is a reply to message #309558] Fri, 28 October 2016 14:17 Go to previous message
powerjon is currently offline  powerjon   United States
Messages: 2446
Registered: January 2004
Karma: 5
Senior Member
If you're looking for a 2.5” in and out the All Stainless muffler part number Magnaflow 12557 is available and Jim K probably has the best price on this muffler.

For a direct replacement the NAPA # SMU18425 is the same as a Walker muffler 18425, both lower priced.

https://www.napaonline.com/napa/en/p/SMU18425/SMU18425

https://www.summitracing.com/parts/wlk-18425

I use the Magnaflow mufflers and all stainless piping except for the 3” run the back, I also have #’ SS tail pipe on the end.

JR Wright
Michigan
> On Oct 28, 2016, at 2:50 PM, Jon Roche wrote:
>
> somewhere I a post of part number for a walker OEM replacement bought from summit for like $35 a muffler. have I think 2 summers on them, maybe 5000
> miles with no complaints.
>
>
> if you are fighting that leak, I would think if you replace that extension inlet with a woven flex pipe, that would put less stress on the exhaust
> doughnuts??
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Previous Topic: [GMCnet] Birchaven For Sale
Next Topic: [GMCnet] Floor jack
Goto Forum:
  


Current Time: Fri May 03 01:42:41 CDT 2024

Total time taken to generate the page: 0.00628 seconds