Can't find my old thread 
Here's the question.
Does anyone know the stock exhaust numbers for a 82/GS-1100E or a link I could look at?
The reason I'm not asking here.... http://www.thegsresources.com/_forum/ is that if I ask, I may loose a good lead on a stock system on Craig's 
If you have the 1982 GS1100E, that had a 'z' designator to indicate the 1982 model year.
I own a 1981 GS1100E, and it has 'x' designator for the '81 model year, so in a parts lookup I ignore all the different models and only pay attention to GS1100Ex. You would do the same except for GS1100Ez. Now, if you have a GS1100GL, that's a different bike (I think the GL was the 'cruiser' model...)
I just did a parts lookup on my Zedder cross-reference. The right muffler has part number:
14301-49201. Now, that's hard to compare to your Sankei number that is stamped on the muffler your seller gave you -- for whatever reason, the Sankei number (I think Suzuki sourced the mufflers from this 'Sankei' company as did other Jap manufacturers) the Sankei number on the muffler rarely seems to match the factory part number. Not sure why.
However, here's the important bit. My parts cross reference always shows the number of Suzuki models that use that same part (it is, after all, a 'cross reference'). Only one bike uses the 1982 GS1100Ez muffler -- that being the bike itself. No other Suzuki models (apparently) use the same muffler as the 1982 GS1100Ez.
Now that doesn't mean the 1150 system (the 1150 leads me to believe it's from a GS1150) you're thinking about buying won't fit, it is a gamble. The style used on parts look similar on different models during a span of years -- like the 4-into-4 stock pipes on cb750s were shared across many years, the HM300s then the HM341s. The *styling* of the part, the outward appearance, looks similar but the part can be different. Will it fit? I always ask myself "if it doesn't fit can I resell it for the same money."
As you probably know, for 1982 Suzuki made several 1100 models:
GS1100Ez
GS1100GKz
GS1100GLz
The 1150 bikes didn't come out in the U.S. until 1985 I believe.
I don't know what the demand is for an 1150 stock exhaust system, but if it's cheap enough and can afford to wait a bit if you have to sell it due to not fitting, it's probably worth the risk.
I check my Zedder cross-reference for the following part number given above:
PIPE,EXHAUST CE
Make: Suzuki
OEM#: 14100-49303-H01
This is the center header pipe pair (hence the 'CE' designation I suspect), the 2 center pipes on the 1100, for the 1983 GS1100E. The 2 outside header pipes are fixed to the mufflers. The 2 inside header pipes are connected together and not fixed to the muffler section unlike the outside pipes -- maybe to make the system easier to install/manufacturing tolerances? Not sure.
Here is a parts diagram for my 1981 GS1100Ex stock system:
