Fordboy9

I am looking to redo the exhaust on my truck this summer. I am going to remove the rear cat since it is already partially gutted. I was thinking of getting a flowmaster 40 and a tip and having a single exit in front of the rear tire. What would the beat exhaust diameter for this setup? 2.5" or 3"? Thanks Scott

rusty84f-150

I'd do 2.5

unit505

X2! 2.5" with mandrel bends. I cut my exhaust off at the rear cat, deleted the muffler and cut the old exhaust to exit out the passenger side in front of the rear tire. I don't believe the muffler will do any good, but then again, I still have my cats. I love the sound withe no muffler. Quiet and slightly throaty. Sounds great!

sylver91

Yeah and under load at low speeds sounds like a tractor

I love mine too.

Fordboy9

All right thanks everyone I just wasn't sure if I'd see any more gain with a 3" since I have the timing advanced and ignition upgraded. And yes I will defiantly do manderal bends, the wavy ones look like crap.

Scott'sF150

You're welcome, but before you go with a Flowmaster 40 series, I'd consider a Magnaflow, or Dynomax.
I put a 40 series on mine when I first did the exhaust and it sounded like a civic on steroids. It was great on a launch from a stoplight, but at idle, it got real annoying real quick.

Fordboy9

Ok thanks, I'm still not sure what muffler I wan to put on it yet, It doesn't have to be loud, I just want a good sound. I currently have a 2.25" magnafow on it in place of the stock muffler, and I didn't notice any difference over stock. And I was told a chambered muffler is best for the 300. Is this true?

sylver91

Chambered will give you that deeper rumble tone.

John K

I removed the rear cat on my 93 with a 4.9. Installed 2.25" pipe back to a flowmaster 44 and exit behind the rear wheel. I think it sounds pretty good. Not loud, not quiet. Have gotten a few compliments on it. I would imagine 2.50" pipe would sound the same just a little louder.