Looking at Flowmaster 80 series part numbers for 3" inlet, dual 2.5" outlet.

There are two:

http://www.summitracing.com/parts/FLO-43083/

http://www.summitracing.com/parts/FLO-53083/

First one is 15" case length, second is 17". Is there any sound difference between the two?

Why the two different lengths?

Thanks for any info!

(Ps... Not looking to start a "flowmaster sucks" thread, there are plenty of those already. Please keep those comments to yourself. I'm just looking for information here )

Interesting. I've always assumed (and you know what that means) that our transverse mufflers were all pretty much the same. Apparently not, as my Hooker's case measures 20 inches.

JamesC

Yep, strange.

Can someone with the Flowmaster American Thunder catback measure the case length of their 80 series muffler?

I'm curious which length case comes with the catback. (outlet size is different from the two above though)

The smaller version is closer to a 40 Series and sounds better.

I beleive Kevin from Chevy High Performance magazine once stated that the smaller one was for the third gen cars, while the larger one was meant for Ls1 catbacks.

Any other thoughts on the difference in case length? I am also interested as I am in the market to change out the muffler on my Jegs branded catback...

The 53083 is what came with my American Thunder Flowmaster Cat back # 17234 that I ordered back in 2005.(at least that's what it says on paper)
I will try to get a measurement as soon as I can. Summit may be able to answer this question as well.

OK, I went out and measured the muffler and it is indeed the #53083 that came with my American Thunder Cat Back "exactly".