I just received a Magnaflow muffler that I want to install in place of my stock muffler. The Magnaflow has a 4" outside diameter at one end and a 4" inside diameter at the other end. What do I need to complete the install? I believe the stock exhaust is a 4" before the muffler to a 3 1/2" after the muffler. Are these #'s inside or outside diameters?

 

Anybody?

 

if I remember right my stock exhuast was 3" before and after the muffler

 

My 99 2500 was something like this:

Downpipe 3" -> 3" pipe -> 3" IN resonator 4" OUT -> 4" connector -> 4" IN muffler 3" OUT -> 3" over axel -> 3" tailpipe -> 4" tip.

If you're keeping the resonator, you'd need a 4" to 3" reducer on the Magnaflow output side. I'm no good trying to figure out which is the OD/ID on pipe, it's amazing that I have my stack on my truck right side up.

brandon.

 

Joefarmer, that sounds about right from the measurments I took this morning. Anybody know if these are inside or outside diameters? Should I use regular clamps or those band clamps I've heard mentioned before on this site?

 

Has anybody got any ideas on the best way to intall this muffler?

 

Sawz-all (reciprocating saw)

I liked the band clamps I got for the 5" system. I tightened the regular u-bolt clamps as much as i could with my impact and it still leaked a little bit.

brandon.

 

Thanks joefarmer. Guess I'll have to find a 4" to 3" reducer with band clamps. Would a muffler shop be the only place to find this?