Custom Built Round Muffler

Custom Built Round Muffler


Our mufflers are a double walled shell. The end caps are roll-seamed. The outer wrap is smooth with no exposed welds. The baffles and end caps are a heavy gauge material.

  • Inlet & outlet nipples cannot be any longer than 7″
  • Regarding 4″ round mufflers with an offset in/offset out position; the nipples cannot be any larger than 1½”ID
  • Regarding 4″ round mufflers with a center in/center out position: the nipples cannot be any larger than 2¼”ID

Use this listing to build your own custom round muffler (within our above parameter’s) . You tell us what you need and we will get it built for you. Select .

There will be no returns on custom built mufflers so be sure you triple check your measurements.


  • Tell us what you want the body (AKA case) length to be (hem-to-hem). Limited to 29" or less.
  • Measuring from the start of the inlet nipple to the end of the outlet nipple, tell us what you want your over-all measurement to be. Generally over-all is 4" longer than the body length.
  • Tell us what you need the inlet internal dimension to be.
  • Tell us what you need your outlet internal dimension to be.
  • This is done with "clocking". For example; 12:00 would put the inlet going in at the top center, 6:00 would put it at the bottom center.
  • Using "clocking" and looking from the INLET end, tell us where you need the outlet to be positioned.
  • All mufflers are built to the OEM specs. Our Mild Impostor's and Impostors allow you to keep your vehicle stock while changing your exhaust notes. Our Mild Impostor is a middle of the road turbo muffler, designed to give your exhaust a deeper, throatier tone. Our Impostor is a high performance, aggressive turbo muffler.
SKU: 0001 Categories: ,


  • Our exhaust systems are made to order. For our current lead time, please refer to the gray banner above.
  • For orders shipping within the 48 USA contiguous states, the shipping charges will calculate correctly. For orders shipping outside the 48 USA contiguous states, please submit your order without payment, we will get in touch with you with your shipping options and get your order completed.
  • The following statement pertains to pipes only (mufflers have a 1 year warranty regardless of material chosen) and to vehicles that are not daily drivers and are stored in an enclosed building: Aluminized Steel has a life expectancy of 20-25 years and is considered to be truer to the original material on vintage vehicles. T409 Stainless Steel is ferric and magnets will stick to it. T409 stainless steel is the same type of stainless used by car manufactures today and will never rust through, although it may develop pock-marks of rust which can simply be buffed out.
  • When building our exhaust systems; where (or if) it requires a pipe diameter of 2” or larger, it will be 14-gauge tubing, where (or if) it requires a pipe diameter smaller than 2”, it will be 16-gauge tubing.
  • Check out our On-line Swap Meet for both aftermarket and OEM (some) H pipes and Y pipes, along with “odd ball” mufflers.






SKU: 0001

Additional information


Aluminized Steel, T409 Stainless Steel

Select Body Length Needed

Body Length Up To 29", Body Length Between 30"-38", Body Length 39" & Longer


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