Clogged muffler

[buck13]

Has anyone noticed an increase in HP from removing their old stock muffler and either not using one or putting on a new one with better flow? Just wondering since my muffler is original on my 93 and starting to look pretty rough.

Buck

[deanj]

Try just replacing with a piece of tube, if to loud get a 'straight thru' muffler. Diesels like more air in - more exhaust out.

[Mr_Roboto]

These are not high revving or high flowing engines. The only time you will see a real increase in power is with a turbo engine, simple because decreased backpressure will increase boost and decrease spool up time.

A 460 is a larger engine, runs at much higher RPM (so it moves more air) and likely uses the same muffler with no ill effects.

To me the only thing no muffler does is make the truck prohibitively LOUD.