I apologize for being slow to respond to this thread (re: aluminum muffler seals), but I've been really busy during the Holiday. (Hope everyone's was happy!).
The seals are a made of heavy-wall S-0 (soft) aluminum tubing, and can be fabricated using a cross-cut with a hole-saw to provide the "wavy" shape. They don't do much except to support the shrouds and reduce heat-losses. Good substitutes might be made out of heat-resistant cloth-tubing such as used for automotive heat-riser/choke-riser and wire-harness insulation. Simply cut it to length and loop it into a circle/doughnut and use Hi-temp RTV or a short piece of alum-tube to mate the ends into/make a circle. This won't support the shroud as much as the OEM part but will help retain the cabin/carb heat pressures inside the shroud.
Fresh air entering the shroud provides a high-pressure area in there and prevents the small leaks from the system clamps from entering the cabin heat air. Those tailpipe clamps are unlikely to be the source of CO entering the cabin. (The cylinder-exhaust-riser clamps are another matter....they should be sealed as well as possible with muffler-tape to prevent high oil temps, and have been discussed elsewhere in these forums.)
Hope this helps.
exhaust tailpipes
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- GAHorn
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Re: exhaust tailpipes
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
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50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.

- 170C
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Re: exhaust tailpipes
Thanks Metal Master for providing the list of places the shroud seals are available. Just for fun I called Duncan Aviation to see what p# 0555157-30 might cost. They have 8 of those seals as shown on MM's list and they are new, not rehabs/used ones. Price each is $93.67
Guess if I make any changes to my system I will be getting more details from George regarding how to make my own (owner produced parts).

OLE POKEY
170C
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170C
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