1970 2 1/2" exhaust

[Ronald R.]

Is the CC system the best I can expect or has gardner came up with anything close? I have NOS pipes with the wrinkle but no swage pieces or mufflers that are close. What muffler part number is correct? thanks Ronnie

[Edward J.]

Re: 1970 2 1/2" exhaust

Ron, I think a few phone calls may get your answers, both venders you mention are the better choices, there are problems with both venders as there may not be anyone who makes a 100 percent correct system for judging. doing a little home work to see who make the most correct. I have a gardner system on my 72 base engine, did not judge well for the money spent, maybe he has made some changes?? Corvette central I think may give you the same but for a lot less $$.

[Joe L.]

Re: 1970 2 1/2" exhaust

Is the CC system the best I can expect or has gardner came up with anything close? I have NOS pipes with the wrinkle but no swage pieces or mufflers that are close. What muffler part number is correct? thanks Ronnie

Ronald------


As far as configuration goes, no muffler, including those once available from GM, are exactly correct. Mufflers and exhaust pipes are one of the very few components for which PRODUCTION and SERVICE differ somewhat in configuration.

[Ron G.]

[Joe L.]

Re: 1970 2 1/2" exhaust

Ron,

FYI – original front 2 1/2 inch pipes for 1970 and most of 1971 LT-1 production do not have crimps or as some people refer to them as wrinkles. Late 71 and 72 front pipes do have them. I am in possession of a pair of new old stock 2 1/2 inch mufflers that fit midyear off road exhaust, 1966, 1966, 1967, 1968
427’s, all LT-1’s, and 70-72 454’s. The only thing needed to do to make them assembly line configuration is to remove the extra bracket. Everything else and I mean everything besides that is typical factory production. - Ron

Ron------


The dual brackets are one of the differences but not the only one. SERVICE mufflers had an extension with with provisions for a slip joint. When joined to a PRODUCTION rear pipe, the pipe would need to be shortened to accommodate the length of the SERVICE muffler extension. PRODUCTION mufflers had no extension. The rear exhaust pipe was welded directly to the muffler and was a PRODUCTION-only assembly. When the SERVICE mufflers are installed as intended, the slip joint configuration is quite obvious and deviates substantially from original configuration, whether clamped or welded.

GM SERVICE rear exhaust pipes were shorter than PRODUCTION to accommodate the muffler extension. PRODUCTION length rear pipes were never available in SERVICE from GM and, as far as I know, not even available in the aftermarket since all aftermarket mufflers had the extension just like GM mufflers.

PRODUCTION and SERVICE mufflers also had different embossments on the muffler outer shell. However, the actual mufflers were dimensionally and internally identical for both PRODUCTION and SERVICE mufflers. As a result of these differences the PRODUCTION and SERVICE mufflers and pipes had different part numbers.

The only case for which the PRODUCTION and SERVICE mufflers were the same (except for embossments) were the 1963-67 and 1968 off-road muffler/pipe assemblies. These were assemblies which included the muffler and rear pipe and were of the same part numbers as used in PRODUCTION.

[Ronald R.]

Re: 1970 2 1/2" exhaust

I had the rear pipes in NOS wrinkle type with what i remember correct length, it has been many years since we put this car togather. We cut the NOS pipe and clamped it to a service muffler with the 2 brackets. The front pipe is welded and not swage type. From what I'm hearing the CC is the closest. thanks for your help ronnie

[Patrick H.]

Re: 1970 2 1/2" exhaust

If you don't have NOS front pipes, then I would consider Gardner for the fronts and your NOS pieces for the rear, making sure to buy the Gardner pieces in plain steel, not aluminized. Also, I have seen artful welders replace the front muffler pipe slip joint with a welded joint which they then grind down and hide. It "can" be done to make it look like a factory system.

Corvette Central's are the "most bang for your buck" when judging, but aren't any more correct. You just take the deduction for aluminized and move on.

[Ron G.]

Re: 1970 2 1/2" exhaust

Joe.

I agree with everything you mentioned. However although I am cognizant the differences in configuration, I assumed that the majority of members on this discussion board were privy to those differences. A skilled welder can certainly fix what you have mentioned and for the sake of OE, nothing sounds like the original mufflers. The ones I recently acquired have no part numbers on them, but rather a "W" on one side for Walker. Lesson here is that I should never assume.

- Ron

[Ronald R.]

Re: 1970 2 1/2" exhaust

The NOS pieces i have are the pipes that should weld to the muffler, I cut them off ( years ago ) but think I can weld pieces back in place and camo them. Is the 2 bracket service muffler as close as I can get? Or do I buy the CC piece with the muffler attached and remove anodize? If so I think this is a good plan. thanks Ronnie

[Patrick H.]

Re: 1970 2 1/2" exhaust

The CC muffler and the Gardner muffler both have configuration issues with the end plates and the seams. Only real GM mufflers look like real GM mufflers.

[Joe L.]

Re: 1970 2 1/2" exhaust

Joe.

I agree with everything you mentioned. However although I am cognizant the differences in configuration, I assumed that the majority of members on this discussion board were privy to those differences. A skilled welder can certainly fix what you have mentioned and for the sake of OE, nothing sounds like the original mufflers. The ones I recently acquired have no part numbers on them, but rather a "W" on one side for Walker. Lesson here is that I should never assume.

- Ron

Ron------


Yes, if the ORIGINAL mufflers are removed by cutting them off right at the muffler, then the GM SERVICE mufflers can have the extension cut off at the muffler and the rear exhaust pipe welded directly to the muffler as was the original configuration. However, if the car has had SERVICE mufflers previously installed at any point in its life (and almost all 1963-72 Corvettes have had this done at least for the right side muffler), then the rear exhaust pipe will have been shortened. So, it will not be possible to weld it directly to the muffler. As I mentioned, GM never offered SERVICE rear exhaust pipes which were the same length as PRODUCTION rear pipes. I don't think the aftermarket has ever or does now offer such pipes but I could be wrong.

I totally agree that no aftermarket or reproduction muffler sounds like an original GM muffler. That's why I have multiple sets of both the 2" and 2-1/2" NOS GM mufflers in my collection [NONE for sale]. This way, I'll have enough for at least the next 200 years. They are among my most prized parts I have in my collection.

By the way, I don't care, at all, about the slip joint configuration when using the GM mufflers.

[Joe L.]

Re: 1970 2 1/2" exhaust

The NOS pieces i have are the pipes that should weld to the muffler, I cut them off ( years ago ) but think I can weld pieces back in place and camo them. Is the 2 bracket service muffler as close as I can get? Or do I buy the CC piece with the muffler attached and remove anodize? If so I think this is a good plan. thanks Ronnie

Ronald------


If you're talking about taking shortened rear pipes, welding in a section to replace the shortened section, then welding this to the muffler and ending up with something that is indiscernible from original (or, even close to being indiscernible from original configuration), I'd like to see that done.

[Joe L.]

Re: 1970 2 1/2" exhaust

Only real GM mufflers look like real GM mufflers.

Patrick------


You are about 99.9% correct. However, once-upon-a-time there were aftermarket mufflers that were virtually identical to the original GM mufflers in external configuration and absolutely identical in sound since they had internal configuration identical to the GM mufflers. What's the story on these mufflers? I'll never tell. I've got to be allowed to have some secrets. They are very hard to find and I don't want to compromise my chance to buy every one I can find.

[Justin S.]

Re: 1970 2 1/2" exhaust

Ronald,
I have a new set from CC if you're interested. PM me with your email. your box is full.

[Ron G.]