So I've been getting mixed answers on this, but will a 3" si/so muffler work for a replacement? Basically what I'm asking is, what size is the inlet and outlet on the factory muffler I've seen 2.5, 2.75, and 3" as an inlet measurement throughout a few forums. If someone can confirm a 3" si/so muffler will work that would be great.

 

If its gonna be welded on by a shop it will work, if you are gonna try to "fashion" it on laying on your back in the garage/driveway, you will still need a welder.

 

Welding is not an issue, I just wanted to confirm the sizes before ordering.

 

What year/engine? I believe the 09 10 f150s were a mix of 2.75 and 3" and the 11+ were 3" except for right after the resonator on the 5.0s . I believe..

 

2013 5.0

 

Then i believe 3"si/so muffler will work. I just can't remember where the resonator shrinks it down to 2.75"
Search in the exhaust section i think its been asked before.

 

my 11' fx4 5.0 was 3" at flange engine side then chocked to 2.5-> res 2.5-> out 2.5 int.med pipe 2.75-> 2.75 into muffler out 3" ..mine from the other fourm

http://www.f150forum.com/f38/new-borla-muffler-226512/

 

The stock exhaust on my '13 was the same.

If you're doing it yourself you'll need a 2.75 ID / 3" ID adapter and some 3" pipe. You'll need some hangers to beef it up but if you get some nice lap-joint clamps you won't have to weld it up at all.

 

Adapter - http://www.summitracing.com/parts/wlk-41687
2.75" Clamp - http://www.summitracing.com/parts/wlk-33977
3" Clamp - http://www.summitracing.com/parts/wlk-33222

You might be able to get these items cheaper on Amazon - I haven't checked.