A friend of mine recently bought an 04 Blazer and the first thing he wants to do is get rid of the 30" boat anchor also known as the stock muffler. I went to Walker's website to get the part number for the stock replacement muffler so I could look it up on Summit to get the muffler dimensions so I could match up a performance muffler to the stock piping.

What I found was this: http://www.walkerexhaust.com/catalog...uponScreen.asp
And here is the Summit listing for that muffler: http://www.summitracing.com/parts/WLK-21364/

It lists a 3" inlet/2.25" outlet muffler, with a flange on the inlet. First off 3" doesn't seem right that they would put that large piping before the muffler on a V6. Second, it's not gonna be easy or cheap finding a muffler with those sizes for the inlet/outlet. Third, it's an offset inlet/center outlet making it even more difficult to find a performance muffler with those dimensions. Lastly, looks like i'd have to weld the flange onto the performance muffler.

Does this seem correct? I figured it'd be finding a standard 2.5" in/out muffler and welding it in, but it seems like now it's going to be next to impossible to just get a performance muffler that'll fit right up. Any suggestions? I figure i'll measure the midpipe diameter, find an aftermarket muffler with that size inlet then weld it onto the midpipe without a flange and get all new piping after the muffler since 2.25" is a little small for a Vortec V6 since it's single exhaust, I figure 2.5" single piping will be good for flow and torque. Sound like a good idea to you all?

Sorry for rambling, I searched but couldn't find anything about the 04 and up Blazer exhaust, and I think they're different than the 03 since I read the 03's had 2.5" piping to the muffler whereas from my research the 04 has 3", i'd rather the experts help before we buy anything. I got a couple 2.5" in/out mufflers in my garage, offset/center that are 14" so I figured use one of those since it's free and I need to get rid of them.

 

Check the Flowmaster and Magnaflow websites and see what they say.

 

it's not that hard (or expensive) finding mufflers that fit your needs. instead of relying on others for the info (web sites that you don't trust/beleive), why not get under the truck, and check it out for yourself?

you do realize that when we get rid of that "boat anchor", you're gonna have to extend the exhaust to reach the tail pipe.
there isn't a price difference for the Flow Master Muffler's regarding the inlet/outlet layout, only the model/size.

when looking on sites, you may need to be "creative" in your searches. example, Magnaflow, doesn't list a Blazer, but lists the TB. and the S10 drops off their list after 2004. so you may have to piece together a system.

another company you could try is Borla.

 

I can't get under there to measure at the moment since it's not here, it's my friend's truck. And i'm fully aware that i'll have to extend the piping to fit, this isn't my first time upgrading exhausts, i've done exhausts for my 87 Mustang 302, my 86 Silverado 350 and my 95 Sierra 305. I was just wondering if anyone could tell me if 3" was in fact the inlet size for the stock muffler. The outlet size appears to be 2.25" but that's really not an issue since he would get a shop to bend up a 2.5" tailpipe instead, and cut it off at the bumper so it's hidden and not having a oddly bent tailpipe sticking out, looks like this one and honestly that looks like it's broken and about to fall off: http://photos4.ebizautos.com/used-20...7584-1-400.jpg which is why I like my single exhausts to remain tucked up and hidden, only dual exhaust should be seen in my opinion.

When he comes around again I guess I could use a c-clamp on the midpipe then measure it's width. He'll probably end up buying a universal 2.5" in/out turbo muffler since those are about $20 and sound good on these since they aren't too loud.

Oh and I much prefer to piece together an exhaust, pre-made systems from Flowmaster and Magnaflow for instance are much more expensive than buying a muffler and tailpipe separately.

 

that truck in the pic looks like the exhaust wasn't installed properly. my '98, which still has the factory exhaust, has the tp tucked right up to the bottom of the bumper (maybe sits down an inch? two @ the max.

i hear you on the cost of kits. plus, all of my vehicles are too old for anyone to make a bolt on system.

the cost of a Flowmaster or Magnaflow muffler really isn't that much, i think i paid $50 each for my SUV 50's (and that's Canadian).

 

I don't mean to offend anyone but I don't think V6's sound good loud. A buddy of mine had a 93 Blazer with the stock cat and a glasspack, that was too obnoxious. I think he's gonna order a 2.5" in/out Summit Turbo and have a shop expand the inlet to 3" and have a new tailpipe bent and tucked up so it's hidden, exiting at a 45 degree angle downward. It'll be just loud enough to hear but not obnoxious at all.

 

the glass pack muffler's are an obnoxious sounding muffler, very crass, very sharp. IMO, the Flowmasters that i have are nice and mellow, but have a decent "growl" not a bark to them.
i had a pair of those Summit Turbo muffler's on my '81 LB, with shorty duals, exiting in front of the rear tires. those were obnoxious above 2 grand, but great for setting of car alarms @ shopping mall multi-level parking structures!

 

I've tried turbo mufflers on V8's and they're ok for a stock muffler replacement but even without a cat it's just not throaty enough. My Sierra has an 18" Magnaflow with 3.5" tips angled in front of the rear passenger tire. My Mustang had Borla Turbo side exits, even with BBK shorty headers and offroad H-pipe it had almost no rumble to it so I threw on some 2.5" tailpipes and Hooker Aerochamber mufflers and it made a world of difference, amazing sounding mufflers it had such a toned deep growl to it, like a tuned up racecar.

Also I found this as an alternative to the Summit Turbo: http://www.summitracing.com/parts/WLK-17192/

It's a little bit longer and it has a 2.75" inlet so it wouldn't have to be expanded so much. I've never heard of these mufflers before so I don't know about taking a chance with them, for all I know they could sound bone stock so he'll probably stick with the Turbo, he's real cheap and likes the $20 price for one lol. I'm pretty sure expanding 2.5" to 3" shouldn't be a problem.

 

Ok after looking again, I think the Summit Racing muffler would be better since the chambered mufflers have more of a rumble to them it'll have a better sound and not be too loud with the cat. Turbo mufflers are really more for someone who wants a better flowing exhaust but a near stock sounding system, they aren't too good for an exhaust you can show off unless you have big pipes on a beefy motor.

Btw if anyone has vids to prove me wrong about my theory on turbo mufflers, i'd be glad to watch them

 

I don't have a video, but I had a turbo muffler from summit on my truck and it was plain annoying. I never thought it it would be that bad, but it resonated really bad.