63 Exhaust Clamp

[Stephen G.]

Any pictures or info on the correct rear (2 1/2") exhaust clamp? I understand it had a numeric stamping. Thread size? Finish?

Thanks

[Stuart F.]

Re: 63 Exhaust Clamp

Which clamps are you referring to? Other than the muffler hangers, the only other clamps I'm aware of are those that work in conjunction with the hanger assembly at the front cross member. I believe the pipes from there on back are welded to the front of the mufflers. Should ask first if your system is 2" or 2-1/2".

Stu Fox

[Stephen G.]

Re: 63 Exhaust Clamp

The rear clamp that pulls together the tailpipe extension, heat shield, and exhaust pipe. It's 2 1/2".

[Michael H.]

Re: 63 Exhaust Clamp

The rear clamp that pulls together the tailpipe extension, heat shield, and exhaust pipe. It's 2 1/2".

Stephen,

I'm pretty sure the tailpipe to muffler clamp is 2". Should be a 3754883, if I remember correctly, and that's a 2" clamp.

[Stephen G.]

Re: 63 Exhaust Clamp

Yep. You are correct 2". I think I might have originals. Here is what I have. There should be a number stamped into the embossing across the bottom (I believe).

I can sort of see a number on one of them.

[Michael H.]

Re: 63 Exhaust Clamp

Yep. You are correct 2". I think I might have originals. Here is what I have. There should be a number stamped into the embossing across the bottom (I believe).

I can sort of see a number on one of them.

Stephen,

The clamps that you have do appear to be originals, or very close to originals. This is what they look like NOS.

[Joe R.]

Re: 63 Exhaust Clamp

Michael,

Don 't think I have ever seen an original on a 63 that had the part number stamped into the bar. As my memory serves, and that's a laugh, I can remember a circle and a 2 stamped inside the circle.

I'll look thru my tailpipe/clamp box and see what I can come up with on Tuesday.

JR

[Michael H.]

Re: 63 Exhaust Clamp

Michael,

Don 't think I have ever seen an original on a 63 that had the part number stamped into the bar.
JR

Joe

I may still have a set of used ones around here somewhere. I'll look. They had the stamped part number also.

[Joe R.]

Re: 63 Exhaust Clamp

Joe

I may still have a set of used ones around here somewhere. I'll look. They had the stamped part number also.

Michael,

Like I said, can't remember yesterday! I do know there were some that didn't even have the reinforcement bar stamped in but they were replacements and not originals. Maybe those were the ones that had the circle on them.

JR

[Kenneth S.]

Re: 63 Exhaust Clamp

Michael,

Ken

[Michael H.]

Re: 63 Exhaust Clamp

Michael,

Ken

Ken,

Yes, that's correct. On the assy line, the pieces were listed separately but for service, one part number included all the components.

[Scott S.]

Re: 63 Exhaust Clamp

I do know there were some that didn't even have the reinforcement bar stamped in but they were replacements and not originals. Maybe those were the ones that had the circle on them.

JR

Did the clamp face design actually change from "with reinforcement bar" to "without reinforcement bar", or might both types have been produced at the same time by different suppliers? The pictures below are of a NOS 3754883 clamp unit that came in the same kind of black & yellow GM envelope as shown in Michael's picture, but the clamp does not have the reinforcement bar. It is stamped "2" inside a circle, with the patent number and "GM 3754883" also stamped into the clamp-face.

[Michael H.]

Re: 63 Exhaust Clamp

Did the clamp face design actually change from "with reinforcement bar" to "without reinforcement bar", or might both types have been produced at the same time by different suppliers? The pictures below are of a NOS 3754883 clamp unit that came in the same kind of black & yellow GM envelope as shown in Michael's picture, but the clamp does not have the reinforcement bar. It is stamped "2" inside a circle, with the patent number and "GM 3754883" also stamped into the clamp-face.

Scott,

I had a similar NOS clamp, just like the one in your picture. It's likely that this design was also used by GM but my guess is that this may have occured before the 63 model year.

The design I posted a picture of seems to be the only style I've ever seen on any 63-67 Corvette, although I don't think anyone has seen very many originals. These clamps typically didn't survive the first removal.

[Stuart F.]

Re: 63 Exhaust Clamp

FWIW, I know my clamps were pitched on the first change many years ago. My first system went pretty fast (in Wisconsin), and the first replacement even quicker. Upon installing my latest aluminized set in 1992, I switched to SS at both front crossmember and the rear hanger, and finally replaced the galvanized heat shields which were removed way back when. I still don't like them as they limit the in and out adjustment of the tips too much.

Stu Fox

[Joe R.]

Re: 63 Exhaust Clamp

Did the clamp face design actually change from "with reinforcement bar" to "without reinforcement bar", or might both types have been produced at the same time by different suppliers? The pictures below are of a NOS 3754883 clamp unit that came in the same kind of black & yellow GM envelope as shown in Michael's picture, but the clamp does not have the reinforcement bar. It is stamped "2" inside a circle, with the patent number and "GM 3754883" also stamped into the clamp-face.

Scott,

Well my memory is not as bad as I remember!!!!! Those are the typical clamps that I have seen on 63-67 tailpipe extensions including early 63's.

Thanks for the pictures and documentation for my failing memory.

JR