I have a 1990 F250 that I transplanted a 6.9 into and am planing on switching out to true dual exhaust either 2.5 or three. What I'm curious about is what to look for in a muffler? Will just a turbo muffler be better or is there more to consider? Is there such a thing as a gas muffler vs diesel muffler? I would ask my exhaust shop but I doubt there knowledge after asking them for quotes and they said just cut out muffler and go strait pipe as the turbo would quite it and I told them it was naturaly aspirated and they kept talking about the turbo. So any details on muffler selection would be good.

 

I went with 2 1/2" center to center 14" long oval dynaflow mufflers on 2 1/2" dual exhaust...Sounds really good!

 

mine is N/A and straight piped, wouldnt have it any other way

 

personal either way you look at it now days any after market muffler unless its a flowmaster 40 series two chamber or something of the sorts is just a oversized glass pack. i also have an oval dynaflow muffler and it comes out the back in 5" and when i rhomp on it still sounds like its straight piped. so honestly it all depends on the size for me when i was running that stock 2.5 i believe it is it was loud and kackally when i stuck my new muffler and that 5 behind her she got quiet and she's only loud when i tell her too

 

The y pipe is a restriction. Fabricating one to go to a 3" single will flow plenty, and seems to be what more people do rather than duals. My personal opinion on a muffler would be a bigger, quieter one. Here's a thread I started a while back: https://www.ford-trucks.com/forums/1...pe-mod-na.html
Check the link in post #4. I didnt buy that y pipe from him, so PM him if you are interested.

 

did mine a bit ago took a 3" flowmaster system off my '95 and did a bit of cutting and welding to make it fit but cut the stock pipes about an inch or so after the y-pipe a 2 1/4 to 3 in. adaptor and just made the rest of it fit. think it was a 50 series but maybe a 70. don't sound to bad still quiet enough that i can hear the engine and any strange noises but a good sound when throttled. looks ugly but free is free.