I'm in need of a new muffler again. I bought the Flowmaster 17345 cat-back aluminized system over 4 years ago. The Ohio winters got the best of the muffler and this fall it cracked right at the exit side. Actually the rear hanger broke (rusted) first and that lead to the muffler cracking. I have it temporarily patched but I need to get it replaced. The aluminized FM70 is about $110 but the entire 409 stainless steel 817345 cat-back system I've found for $300. So I'm really thinking about just getting the entire stainless steel system. I already need to get a new hanger even if I go with just the muffler. So my question is does anyone have the 817345 kit? Is the muffler and hangers stainless steel as well or just the tubing? If it's just the tubing than it's not worth the cost. If it's the entire system how is it holding up?

 

The clamps they show on the site for the stainless system(band clamps) are different than the u-bolt clamps so they are probably stainless. I didn't even bother using the clamps that came with my aluminized kit. (even the hanger clamps) I made a new hanger/clamp out of 304 stainless so it will never rust out and welded the rest. The 409 stainless will still rust up it will just take longer to rust through. The clamps that come with the aluminized kit are not even useable IMO.

 

Put the 817345 stainless setup on my truck last fall, fits very well and all the clamps and hangers are stainless. This kit uses some real nice, heavy duty stainless band clamps and the tailpipe hanger is clamped on instead of welded, a much better solution since everything is stainless and it gives some room for adjustment.

My old flowmaster system failed because the tail pipe rusted around the hanger welds and then the hanger broke off, welds and all. I didn't notice it until the back of the muffler cracked out and it sounded awful.

This new setup even included a short spacer for the muffler inlet, a detail they missed on my old 17345 system. Overall seems like a great quality system and it sounds good, wish I had went with stainless the first time. Got mine at streetside auto, was the best deal I could find, shipped for free and since they are just down in KC it delivered extremely fast.

 

I didn't use the clamps either but I wish I would have thought to use a stainless steel hanger. That's was the core of the issue with the muffler cracking.
The muffler is all stainless steel as well? Good to know the clamps and all are higher quality than the aluminized system. Like you I now wish I would have went with the stainless steel version the first time around.
Also thanks for the feedback on Streetside Auto. I found them earlier. They seem to have the cheapest price by far.

 

Yes, according to the install pdf from flowmaster's site the included muffler is 853073 and its listed as 409S Stainless steel.