70 Corvette exhaust system Id

[Roberto L.]

Hello, after restoring the rear suspension in my 70, it was time for the exhaust system. Following some good advices from Jack (Humphrey, RMC) I will replace the rear pipes and mufflers. Now, I inspected the old system and found some details that could indicate an original system (incredible after 33 years, almost). Pipes are the factory 2" type (base engine) with bends showing ripples and some flatening. Clamps are the ..71 variety as shown in B. Cook Restorer article (will reuse them). End of pipes have famous tab matching the SS square tails. Mufflers have W marking (will save the less rusted for reference) and hangers seem original with PM marking (will reuse them).

Just for learning (will change the worn mufflers and pipes any way), do you think, as I suppose, that this is the original system?

Thanks, Roberto, NCRS #30019, RMC

[Shannon Burgess]

Re: 70 Corvette exhaust system Id

Roberto, are the mufflers and pipes a one-piece unit, or are the mufflers bolted to the pipes that run from the transmission crossmember back? If it's a single unit, it sounds like original to me.

[Roberto L.]

Re: 70 Corvette exhaust system Id

yes, forgot to mention, these were one piece system from center of car to muffler. thanks

[Joe L.]

Re: 70 Corvette exhaust system Id

Roberto-----

Based upon your overall description, including the information provided in your most recent post, I'd say that the exhaust system is undoubtedly original. This is VERY possible, even for a Corvette of 30+ years old. However, what is surprising is that the right side muffler would not have been replaced at some time with a SERVICE muffler. The original right side muffler on my 69, which has EXACTLY the same exhaust system as yours, did not last 4 years even in the California climate which is about as easy on the EXTERNAL surfaces of mufflers as any, anywhere. My right side muffler rotted out from the inside at the usual spot on the low point of the muffler, as installed. I replaced it 2 more times with GM SERVICE mufflers before I installed a complete stainless steel exhaust system on the car in 1986.

[Patrick H.]

Re: 70 Corvette exhaust system Id

In addition, if there is ANY way you can remove them as a whole, with the only joint/cut being at the center frame crossover as original, I'm sure they would be valuable as a reference and/or part for a judged car. I'd avoid cutting them anywhere else if possible.

Patrick

[Geoff C.]

Say Patrick, ahhhh when is that NCRS meet

in Argentina?

[Roberto L.]

Re: 70 Corvette exhaust system Id

You are right Joe, the right muffler was a lot worse than the left one, for any reason, with the hole in the lower side as you described, so there is a chance that could have been replaced in the past and what I have is a second or third service muffler but the pipes in the right side have all the original caracteristics.

Roberto, NCRS #30019, RMC

[Roberto L.]

Re: Say Patrick, ahhhh when is that NCRS meet

Yeah, we have some little... problems to resolve, nothing important... well any way I'm keeping the left muffler, which is rather good, for reference. I hope to use it in some school like class on Corvettes in our local club. I will reuse the rest of the hardware, cleaned clamps and hangers and will keep the headers which are rather well.

The rear pipes are not very good after driving some years in Buenos Aires older streets which are of the stone variety... Usually when the muffler starts to rot out it 'seats' lower.

Roberto, NCRS #30019, RMC

[Joe L.]

Re: 70 Corvette exhaust system Id

Roberto-----

If the right side muffler is connected to the rear exhaust pipe right at the muffler, rather than at a "bell joint", then the right side muffler must be original. You could never purchase a 2" GM SERVICE muffler complete with rear exhaust pipe. In other words, if the configuration of the right side muffler/exhaust pipe assembly is the same as the left side, then the right side is VERY likely original, too.

[Roberto L.]

yes, that's the way it is, thanks *NM*

[Patrick H.]

Re: Say Patrick, ahhhh when is that NCRS meet

Geoffrey,

Whenever Roberto decides he wants one.

I figure that if guys in Europe ship parts from the US to there all the time to fix their cars, it wouldn't surprise me in the least if someone in the US saw enough value in them to buy them. Heck, ebay is filled with those types and thrives on them

If nothing else, as Terry often says "That would make a great Restorer article."

Patrick

[Michael W.]

Re: Say Patrick, ahhhh when is that NCRS meet

Woody,

I seem to remember that Jack Humphrey is the patron saint designate of the Argentinian NCRS Chapter-to-be. Maybe you and Jack could be guest speakers at their next judging meet. Waddya say?

Best regards to Jason the gardener.

[Geoff C.]

Re: Say Patrick, ahhhh when is that NCRS meet

Mike,
If nominated, I will not serve. If drafted, if will not run. However a man of your international backround and experience as a Canajun NCRS Ambassador, I nominate you to contact Jack to formulate a seminar on hot air when that . Argentinan NCRS event is held. That task is just too exhausting for me.
Geoffrey