Which is more correct? I have a 68 corvette. I noticed at the back of the exhaust tip (where the clamp attaches) there are 2 slits which allow the clamp to compress the exhaust tip to the muffler. I also have a set of NOS exhaust tips and they have 4 slits in the flange where it attaches to the muffler. Which is more correct? Anyone aware of the design change and at what point it took place? Any comments appreciated. Terry
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Re: 68/69 Exhaust pipe tips.
Terry-----
The 1968 and 1969 exhaust tips were not the same. For 1968, the exhaust tip was GM #3921607. For 1969, the exhaust tip was GM #3952742. I don't know how the 2 differed, but I do know this:
The exhaust tips used in PRODUCTION for 1969 Corvettes, and presumably GM #3952742, had TWO slits on opposing sides of the swaged down portion. That's the configuration of the known-originals from my original owner, late-build 1969. Interesting, the longitudinal dimensions of my originals are slightly different from side-to-side and are also different from the dimensions found in the 1968-69 NCRS Judging Guide.
One of my originals has a "long" dimension of 10-3/8" and a "short dimension of 7-5/8". The other has a "long" dimension of 10-1/2" and a "short" dimension of 7-3/4. This results in the angle of the tip end being the same for both tips, but the overall length of one being a bit different than the other. Also, the shorter of the 2 tips has a slightly different configuration for the "slits". On this tip, the "slits" have a "notch" or wider section on the outer end. This "notch" may have been intended to index the tip to a mating "nub" on the muffler's exhaust pipe (like some later C3s). However, no such "nubs" were ever present on the original mufflers. Plus, as I say, the "notches" were only present on one of the 2 tips on my car.
The 68-69 NCRS Judging Guide specifies tips with a "long" dimension of 10-5/8" and a "short" dimesnion of 8". These dimensions are longer than any of the dimensions on my original tips. However, these may have been taken from 1968 tips and that MAY be the difference between 1968 and 1969 tips.
Confusing the matters even more is this: I have a pair of NOS GM #3952742 tips in original GM boxes dated about 1977. These tips have the 2 slit configuration just like my originals, but without any "notch". However, they are slightly shorter in overall length. The "long" dimension is 10-1/8" and the "short" dimension is 7-1/2".
I have another pair of exhaust tips which I believe to be NOS, but they are not in the original boxes so there is no way to say for sure or to say whether they are the 68 or 69 part numbers. These tips have the 4 slit configuration, but no "notches". They have a "long" dimension which is 10-7/16" and a "short" dimension of 7-5/8". This makes them very close to the dimensions of my original tips.
ALL of the SERVICE tips that I have do have one feature which makes them slightly different than the original tips. The shape of the "transition" area from the 2-1/2" to 2" OD is different. On the originals, the transition area is shorter and rounder in shape. On the SERVICE pieces, both the known NOS originals in the boxes and the ones not in boxes, the transition area is slightly longer and more "conical".
Are the NOS originals that you have with 4 slits in GM boxes with GM part numbers and what are the "long" and "short" longitudinal dimensions"?In Appreciation of John Hinckley -
Re: 68/69 Exhaust pipe tips.
Joe, after jumping through some boxes I finally found my exhaust tips. The ones in GM boxes are NOS and the part number is 496346. They have the 4 slits in the flange and they measure 7 1/2 on the short and roughly 10 3/8 (maybe tiny tad longer) on the long end. The boxes fit the item so I think they belong to the boxes. I don't recall if I was the one that opened them.
My other ones that I purchased off a 68 corvette and are a tad rough have the two slits. They measure 7 1/2 on the short side and 10 1/2 on the long. So, let me know what you think? Regards, TerryComment
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Re: 68/69 Exhaust pipe tips.
Terry-----
GM #496346 is a SERVICE replacement for the GM #3952742 that was released when that part was discontinued in February, 1980. The GM #496346 was discontinued in February, 1993. I was not aware of the existence of the 496346, but now I think I know what the other pair of NOS tips that I have actually are. In any event, the GM #496346 are SERVICE replacement only; they were never used in PRODUCTION. That's also why they differ in configuration to the originals.In Appreciation of John HinckleyComment
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Re: 68/69 Exhaust pipe tips.
Interesting. I think I will clean up my old one's and have them rechromed and hang on to the replacements. Thanks, TerryComment
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