I recently bought a complete 2" exhaust system from Corvette Central (CC) for my '72 coupe with the L48 small block and M20 manual transmission and discovered that the ID of the inlet pipes on the Magnaflow mufflers, that were included, are far too large to fit the 2" OD of the intermediate exhaust pipes.

While the OD of the intermediate pipes is correct at 2", the ID of the inlet pipes on the mufflers is 2.216" (2-7/32"). That leaves a large gap of almost 1/8" (7/64") all around.

CC's part number for the Magnaflow mufflers is 323112. They are described as 2" mufflers, but it's obvious that they are not. I'm still working with CC on a solution, but so far, they are offering none. I've also contacted Magnaflow just to find out how they provide the mufflers. I'm currently stuck with a pair of mufflers that I cannot mount without modifications.

If CC draws a blank, I'll have no choice but to have the mufflers cut and welded to the intermediate pipes or fabricate a pair of sleeves to fill the space between the pipes. I don't care much for either of these options, so I'm hoping that CC comes through with an exchange for a pair of mufflers that fit correctly.

Has anyone else run into this when buying a complete exhaust system from CC or any other vendor? Was a solution offered? If so, what was it?

In the meantime, others should be aware of this potential problem when buying from Corvette Central.

 

The only issue I had with CC exhaust were the pipes were too short and gapped between the front pipes and the midpipes. I ended up having the whole system welded up after I installed it.

 

I dunno how it is in Mad Wisc.....but in the DC region, there were NO competent exhaust shops, just a bunch of parts changers, Walker pipes or DIE, all based on stock junk.....so the limitations were horrendous.....

the only way to get this to fit with they typical pipe clamp is to pray your parts house has a selection of fittings/reducers and you can clamp over both pipes to reduce the size problem....

a GOOD exhaust place would have no problem, here in Florida, I got extremely lucky and have a pipe genius down the street....that man could fit a muffler on a 747......

 

Yes Sir; They have just given you the wrong set of mufflers. They sell both the 2 " & the 2.5 " sets of exhaust systems. I have bought 3 sets, for three different years,from them & they have all fit like a glove. Be Nice & Give them a few more calls, until they get the mufflers exchanged. Keep us abreast of what happens. Have a great one. Gene

 

Not much of a problem!...just go to a muffler shop that has a pipe bender...They will be able to place a small sleeve in the muffler nipple and expand as necessary to make a custom fit...take the extension pipe with you and fit it

PS, done right you will never see the modification,,,do not cut the mufflers up , that would not be very good ......

 

I bought a complete 2.5" system with Magnaflows...Perfect fit
I have never had a problem buying from Corvette Central

 

Bought the dual Magnaflow exhaust system for my 78 L82 4spd. Hooked it up to the original exhaust manifolds and everything else fit. The muffler pipe to the intermediate was loose but once clamped it was fine.

CC has been selling these systems to forum members, and I cannot recall any one with a problem. Or at least I didnt read of any complaints. They have a tech desk you can deal with. Just have them measure another muffler pipe ID for you to see if you got the right one.

 

Yeah. I bought the CC's 2 1/2" dual system with Magnaflows a year ago and had no issues with the installation at all. I thought it worked out nice.

 

It took a LOT of doing, but after many email messages and a phone call, (the technician) at CC finally concurred that I was sent the wrong mufflers. The part numbers on both boxes were correct, but is seems that two identical, but incorrect, mufflers were placed in the wrong boxes.

While I can certainly understand and appreciate a simple error like this, (the technician) was VERY difficult about the whole thing. Even after my detailed explanation and eight pictures that clearly showed the problem, (the technician) just dragged his feet and offered no solution. I had to talk to his supervisor in order to correct the problem. She was very apologetic and good about the whole thing and sent the UPS label to return the mufflers.

I shipped the two incorrect mufflers this morning, so I’m hoping to see the correct ones in a week or so, and am hoping that there will be no more problems.

I know there are a lot of people who have had nothing but good experiences with CC, but so far, I am not one of them. I’m hoping that eventually my opinion will be more positive. Time will tell.

 

We are sorry to hear of the difficulties you experienced with these mufflers. Thank you for acknowledging that the issue was ultimately taken care of.

 

I've never had any issues with CC. It's always been a good experience.

I will share a different experience with a different supplier tied to Magnaflow. This is the ultimate customer experience for me:

I bought a complete Magnaflow exhaust back system for my 72. Upon receiving the item, I noticed that the exhaust tips had 2 small dents in them on one side. I called the supplier and they immediately asked me to return them via pre-paid UPS, and that they would ship a replacement ASAP. I asked if they wanted pictures, and they said no. UPS showed up the next day to pick them up and my replacement system (not muffler) arrived in 3 days.

 

We are glad that you were able to get the mufflers sorted - and thanks for choosing MagnaFlow!

 

Does CC offer a discount to forum members ? I'm just about finished with my front end rebuild and now the exhaust system is my next big project.

 

It seems that CC and Magnaflow are under the impression that the fit problem has been solved, but based on what I've experienced so far, I'm still in the "wait and see" mode.

While it "appears" that the correct mufflers have been identified, this is not a done deal. I have yet to receive the replacement mufflers and I have yet to install the exhaust system. Therefore, I am not able to confirm that everything fits and performs as it should.

Given the problems that I have had with this complete exhaust system package so far, I can only be cautiously optimistic about the outcome. You know what they say about assuming anything...

 

Thanks for actively monitoring this site! Always appreciated.

 

I'm happy to report that I received the correct 2" Magnaflow mufflers from Corvette Central this afternoon and they fit the intermediate pipes as they should.

CC’s part number for the system that I bought is 323714MAGDXB and I will be using a set of 1-1/4” wide strap clamps from AccuSeal instead of the U clamps that came with the exhaust system.


The turnaround time from when I shipped the incorrect mufflers back to CC and received the correct mufflers was only five days, which included the weekend! I have yet to mount the exhaust system, but I’m a bit more optimistic about the installation going well.


Although it's an irrelevant issue at this point, I was never able to identify an exhaust system that would require the mufflers that I first received with the 2.216” ID inlet pipes. The only thing that seems plausible is that these particular inlet pipes were simply expanded more than they were supposed to have been when manufactured. They were too large for a 2” system and too small for a 2-1/4” system. But, I’ve no need to concern myself about it anymore and am just glad to have the mufflers that I need.

I’m looking forward to getting this new exhaust system mounted and see how it performs and sounds. I did a lot of research and weighed a lot of pros and cons before selecting the exhaust system that I bought and am hoping that I made a good choice. I’ll try to report back once it’s installed.

 

the bad thing with mail order stuff is if there is a problem you have to return the wrong stuff before you get the right stuff, you lost 5 days . on a second note i would have gotten a system with larger tubing. enjoy your new system. and its good to know both companies were looking out for you.

 

Glad to hear the situation was remedied in a timely fashion. Kudos to CC as always, and Magnaflow for standing behind their great products.

 

I did a lot of research while weighing many pros and cons before selecting the exhaust system that I bought. While I see no need to justify my selection, I will share my thoughts for clarification. Among the most important considerations were;
1. Possible NRCS Survivor certification. The 1972 L48 requires an OEM-style 2” exhaust system. Any other size would cost me points. The correct U clamps and stock mufflers will also be needed.
2. My unmodified L48 with original 2” cast iron manifolds would benefit little from a larger diameter exhaust system, as on the LT1 or ZR1, which have significantly higher airflow capabilities. The mufflers will provide less backpressure within the airflow limits of the L48, and an improved exhaust note. That’s all I’m looking for.
3. The low restriction of the entire exhaust system should not exceed the airflow capabilities of the engine. Installing an exhaust system that is too large for an engine’s airflow capabilities would be a detriment to performance, particularly when it comes to torque at the low and mid rpm range, which is where I spend most of my time.
4. Having a history of building high performance motorcycles, I am aware of the necessity of matching ALL components, from the air cleaner to exhaust tips. The same principles apply here.
5. The bottom line is that bigger is not always better. The size of the exhaust system and other components depends on the desired outcome. Although a 2-1/4” exhaust system would likely be optimal for an unmodified or slightly modified L48, it does not meet my criteria.

Lastly, I don’t believe in giving kudos to a vendor for doing what should have been done in the first place. Correcting an error does not qualify a vendor for praise. Magnaflow contributed nothing in resolving the fit problem. And while CC did correct the problem quickly, which is much appreciated, it was their error to correct. In my opinion, kudos are reserved for efforts above and beyond what is expected. This might sound hardcore, but I don’t believe in patronizing a vendor for delivering the correct parts for which I’ve paid. Say what you will, but when I see “Customers First, Quality Always” on CC’s parts boxes, that’s what I expect.