63-72 Corvette Mufflers

[Joe L.]

Well, it looks like someone (several folks, actually) have taken my advice regarding original Corvette mufflers to heart. Check out eBay item #4587735613.

I give out quite a bit of information on this board (perhaps, too much considering what it MIGHT do to affect the price of mufflers that I otherwise might be able to buy cheaply), but, perhaps, some folks have taken it REAL seriously. Of course, the buyer might not ever have visited this board, at all. I hope so. Anyway, I have enough original mufflers. Enough to last me about 500 years. Or, if I were to sell them at these prices, enough to take me on several around-the-world luxury cruises on the QM II. I don't want to go on any of those cruises, though, so I'll hang on to the mufflers.

By the way, the VAST, VAST majority of aftermarket mufflers out there now and in the past are not configured internally at all like the original 63-72 Corvette mufflers. So, as I've said before, the sound is not the same. However, there were available "once-upon-a-time" some aftermarket mufflers that were identical to the GM mufflers in all respects. In one respect, they might even be better. The original GM SERVICE mufflers often have a part number embossed on the shell. Most PRODUCTION standard mufflers did not. The aftermarket mufflers I am referring to have no GM part number embossed on the shell, so they're more like the original PRODUCTION mufflers in this regard.

You don't see these mufflers very often since they were discontinued many, many years ago. So, how do you distinguish these from the VAST, VAST majority of aftermarket mufflers, new and old, that aren't worth a tinker's damn? Now, you don't think I'm going to divulge that kind of information, do you? I mean, I DO have some secrets!

[Michael H.]

Re: 63-72 Corvette Mufflers

I see these mufflers have the dual mounting brackets on the rear for both 63-67 and 68 hanger locations. Did assy line 68 and later mufflers have both brackets or just the single bracket? I know 63-67 didn't and I thought 68 had just the single bracket also, which would make these mufflers incorrect for either C2 or C3??

[Charles M.]

Re: 63-72 Corvette Mufflers

$1025.00 !! Sell every one you have Joe. I avoid ebay at all costs. BUT NOW I think I'll dig out that old gravy stained holiday tie and see who bites.

(we all know that these sharks bid up prices amongst friends for a good show and the money never changes hands, we all realize this don't we?)

[Dennis D.]

Re: 63-72 Corvette Mufflers

The only thing I've never seen is the locating tab. Why the aftermarket doesn't just weld one on always escaped me

[Terry M.]

Re: 63-72 Corvette Mufflers

Michael,
The PRODUCTION 1968+ mufflers had just one mounting bracket. Even beyond 1973, I think. Of course 1968-1972 was different than 1967 and earlier, and 1973 was a one year only. I lose track after that, but someone else can fill that in.

[Joe L.]

Re: 63-72 Corvette Mufflers

Michael-----

No PRODUCTION mufflers ever had dual brackets. The 63-67 used one bracket configuration and the 68-72 used another bracket configuration.

Once-upon-a-time (prior to late 1968) there was available 2-1/2" SERVICE mufflers for 63-67 applications only. These mufflers had the 63-67 bracket and no other bracket.

There was also a pair of mufflers once available in SERVICE for 1968-only applications (all 2-1/2"). These mufflers had the 68-72 style muffler bracket.

Between very late 1968 and the early 70's, the above were all discontinued and replaced by 2-1/2" SERVICE mufflers which had the dual brackets to SERVICE 63-72 2-1/2" applications. The only difference between the 63-67 and the 68-72 mufflers was the brackets. So, I guess GM decided it would be more economical to include both brackets on the mufflers and stock only 2 part numbers rather than 4 part numbers.

Curiously, the same thing was never done for the 2" mufflers. The 2" 63-67 mufflers were always equipped with only the 63-67 style bracket throughout their SERVICE availability. Likewise, the 69-72 2" mufflers (there was no 1968 2" muffler since all 1968s used 2-1/2" exhaust) used the 68-72 style bracket; no dual bracket was ever used throughout the SERVICE availability of the 69-72 2" mufflers.

For off road exhaust, used in PRODUCTION from 1964-68. The muffler/rear exhaust pipe assembly also had only one bracket. The 64-67 used the 63-67 bracket; no dual brackets. 1968 used the 68-72 style bracket; no dual bracket here, either. In these cases, though, it's more understandable why dual brackets were not used. That's because there was a slight difference in the configuration of the rear exhaust pipe between 63-67 and 68-72. Since the rear exhaust pipe was included with off-road assemblies, they were specific for this reason and there would be no point in using dual brackets.

[Joe L.]

Re: 63-72 Corvette Mufflers

Dennis-----

GM SERVICE mufflers had no locating tab. At least, they did not through 1972. I don't know if the 73 SERVICE mufflers had the tab, or not

[Joe L.]

Re: 63-72 Corvette Mufflers

Chuck-----

I think that this one was an honest-to-goodness sale. I could be wrong, but I think so. Also, there was a very high reserve, anyway.

[Charles M.]

Re: 63-72 Corvette Mufflers

Amazing.

[tom444634]

Re: 63-72 Corvette Mufflers

Ok, all of this exhaust talk makes me need to ask the following. I am planning on replacing the mufflers on my 71 BB, which ones should I look at getting? Does any particular vendor have the "correct" ones for my car? Thanks, Tom

[Joe L.]

Re: 63-72 Corvette Mufflers

Tom------

There are lots that are more-or-less original EXTERNALLY. There are NONE that are original INTERNALLY. That means that there are none that sound like the originals. Sound is a very intricate and subtle sort of thing. For example, there are lots of violins, but none that sound like a Stradivarius.

As far as external configuration goes, keep in mind that original exhaust systems used rear pipes that were welded to the muffler at the muffler. All GM SERVICE muffler assemblies (except 64-68 N-11) were sold as seperate pieces in a SERVICE only configuration (i.e. SERVICE rear pipe shorter than PRODUCTION and SERVICE muffler with extension and bell joint).

In the reproduction market you can get a system which is welded at the muffler, as original. The external configuration of the mufflers is very close to the original. The configuration of the reproduction exhaust pipes is not the same as the original. All reproduction systems are mandrel-bent. PRODUCTION and SERVICE GM pipes were die-formed. This difference results in configuration differences.

Also, all original systems used plain, carbon steel pipes. These things were usually already rusty by the time the original owner took delivery. Reproductions are available in carbon steel, aluminized carbon steel, and stainless. Only plain carbon steel is original, but you'd NEVER, EVER catch me using it.

Original mufflers used a zinc plated or galvanized steel shell. Original right side mufflers used stainless steel plates on the forward end. Most reproductions are zinc plated or galvanized, as original, without the stainless steel ends. So, externally, they look pretty much just like the originals.

[Kevin M.]

[Michael H.]

Re: 63-72 Corvette Mufflers

Ok, thanks Terry, Joe. I was pretty sure that was the case for C3 but because of my incredible in depth knowledge on C3, I only know for sure that the mufflers are located somewhere near the rear of the car. Because the original one piece muffler/pipe assy was unique to production, not service, and also unique to the era, (C2 or C3) there would be no logic in making an assembly that fit both for production.

One of the only C3's I've ever owned was a low mileage L89 69 and it had original exhaust front to back. I vaguely remember that it didn't have the additional bracket in place for C2.

[Bill Stephenson]

Re: 63-72 Corvette Mufflers

Joe or Mike,

-------If One had a set of NOS off-road 68/72 pipes could one use 68/72 hangers on a 64/67 and have the pipes bolt up and fit??? .......Bill S

[Joe L.]

Re: 63-72 Corvette Mufflers

Bill------

The only C3 year that that ever used N-11 exhaust was 1968. Although once available in SERVICE, the 68 muffler/pipe assemblies have been discontinued for years. They are very hard to find. I've NEVER seen a set, or even a single assmbly, for sale. The 64-67 N-11 assemblies are much easier to find. Notwithstanding that, if one had a set of the 68 N-11 assemblies, they might be usable for a 63-67 regardless of how unlikely that scenario might be. However, I think that the 63-67 hanger bracket might have to be added. I don't think that the 68-72 hangers could be used to mount the 68 mufflers to the 63-67 configuration.

Also, the configuration of the rear pipe is a little different between the 64-67 and the 68-72. They're generally "interchangeable", but there will be some slight fitment problems.

The mufflers with 63-67-only muffler brackets, including the 64-67 off-road N-11, can be used on a 68-72 if the 73 muffler hangers are also used (a trick that few folks know about). I don't think that the 73 hangers can be used to adapt the 68-72 muffler brackets to a 63-67, though. If the 64-67 off road assemblies are used for a 68-72, there's still the rear pipe issue I described above.