I am looking for quiet on the inside and semi smooth on the exterior. Which muffler will do the best without the interior drone? I wouldn't mind a little Mpg and performance to top it off.

 

i have a flowmaster 40 3" delta flow on mine. it's pretty damn loud, but it doesn't really 'drone' on the highway.

 

A Flowmaster 70 Big Block muffler is the one that fits your requirements. The FM50 will be too loud on the inside for your taste.

 

I have a Flowmaster 40 Series delta flow as well, its nice and loud but it doesn't get annoying. On my old truck (1990 c-1500 355) I had a non delta flow 40 series and it was annoying as hell, although it was a base truck and it didn't have any sound denting in it.

 

dont go with 70 series. its only a lil louder than stock.
i had a 50 series then i got the dual out the back magnaflow catback. the magnaflow is DEEPER and quiter. i only wished that it was louder at idle
but both are just nice and mellow

 

I guess we need to find out what he means by 'semi smooth' on the outside. If he means louder is okay, then the 50 could work. If he means he wants it mellow and quieter outside as well, the 70 series would be better.

 

If I was to go with Magnaflow, which muffler should I go with? I guess I mean what length should I go with? I want a deep tone with minimum interior noise.

 

Ive got the Magnaflow Catback i think 15618... and i love it.. not to loud but when you get on its mean... mine is the 5X11X22 i believe..

 

I have a Flowmaster 70 and I get interior resonance at around 2k rpm which really sucks. It does have a good tone to it at wot and is pretty quiet at idle. I'm about to put a Hooker Maximum Flow in and see how it performs.

BTW I can give you a good deal on that Flowmaster if interested.

 

Sound or no sound i lost .6 in the 1/8 by switching from Flo Pro to that same muffler.

Go Magnaflow, they give performance and sound. Flo only gives sound.