'67 Exhaust help

[R N.]

Hello Everyone,

I'm installing the N11 exhaust system purchased from Cor. Central for my '67 L79 and have a question regarding the installation of what some call the "alignment ring" for the packing. (It's item 322118 in the attached photo)

From past exhaust work I've done, I remember this sleeve fitting snug into the front pipes, but the sleeve I have is so tight I would have to give it a few good wacks with a hammer and a piece of wood to make it fit. Just how tight should this fit. Anyone else have this problem.

[Jack H.]

Re: '67 Exhaust help

You'll find a couple variations in the construction of the exhaust sealing gasket: (1) made from rather soft fiber material, (2) made from a solid cast material.

In general, the soft fiber gaskets are pliable and rather easy to install while the solid cast parts require 'coaxing' into position. The pro/con issue is the fiber gaskets don't last (heat fatigue) as long as the harder cast gaskets do.

[R N.]

Re: '67 Exhaust help

You'll find a couple variations in the construction of the exhaust sealing gasket: (1) made from rather soft fiber material, (2) made from a solid cast material.

In general, the soft fiber gaskets are pliable and rather easy to install while the solid cast parts require 'coaxing' into position. The pro/con issue is the fiber gaskets don't last (heat fatigue) as long as the harder cast gaskets do.

Thank you for the reply Jack - it's the sleeve that I'm having trouble with. Sorry if my question was mis-leading.

[John H.]

Re: '67 Exhaust help

Just how tight should this fit.

Kurt -

If the sleeve is made correctly, it should drop right in place with no "coaxing".

[R N.]

Re: '67 Exhaust help

Thank you John. I will see about having a local exhaust shop "swaged" the ends of the sleeve to fit or ask Cor, Central to send some new ones out.

[Wayne M.]

Re: '67 Exhaust help

Kurt -

If the sleeve is made correctly, it should drop right in place with no "coaxing".

I was under the impression that GM original under-car 2_1/2" exhaust front pipes already had the "extensions" installed, as part of the assembly.

But on the side exhaust, '65 AIM N14 Sheet 3 has a note: secure extension #3757555 to exhaust pipe by spot weld (3 places) equally spaced, or embossed (2) places equally spaced.

I have an NOS BB set of N14's and could never figure out why the spacers/extensions weren't part of the GM side exhaust pipes/mufflers as well.

[John H.]

Re: '67 Exhaust help

But on the side exhaust, '65 AIM N14 Sheet 3 has a note: secure extension #3757555 to exhaust pipe by spot weld (3 places) equally spaced, or embossed (2) places equally spaced.

Wayne -

That "note" was removed from the Assembly Manual in January, 1966; I suspect it was an error putting it in the AIM to begin with, transferred from the part drawing for the supplier's use. There was no such assembly operation (spot-welding or embossing the extension) at St. Louis.