Internal mufflers are designed for straight stacks. Muffler slips into the bottom of the stack and bolts into place. Template and stainless steel hardware are included.   Not designed to work with emission equipped engines, or for stacks with a built-in reducer.  Body length is 45". Fits 6" diameter dual stacks. Works on dual exhaust only. Aluminized steel.  Sold individually.

* 2 holes must be drilled into the stack to secure the insert.  

For maximum performance,  this muffler is recommended for the following engines: