I have a 2000 F-150 with the Flowmaster Cat-back system on it. The Flowmaster muffler rusted out and I am going to replace it with a Magnaflow SS muffler. I need a SI/DO muffler to fit the rest of my cat-back system. I am not sure which muffler to go with. I know the inlets and outlets are both 2.5". The only Magnaflow with 2.5" inlets and outlets is a 14" muffler. The one Magnaflow sells with their cat-back system is an 18" muffler.

Which magnaflow muffler should I use for my truck? Should I just go ahead and get the 18" muffler and get the exhaust shop to make it fit or should I get the 14" which I am sure will still need some custom work to make it fit? What is the difference between an 18" muffler and a 14" muffler as far as performance and sound?

Thanks in advance for any help you can give!

 

the smaller muffler will be a little louder. not sure which muffler you will need thou for your SI/DO. just measure your Flowmaster and get one the closes from Magnaflow.

 

Thanks sgauthier!

I will measure the piece of crap flowmaster later. I would like it to be a little louder, but don't know how the 14" will affect performance. If anyone has any ideas on performance or other recommendations please let me know.