I am referring to exhaust pipe surrounded by heater ducting .what is a fix other than buying new ?

If you are referring to the heat exchangers, then the only option is replacement. Find a good used Stainless Steel set and put them on.

Clay

Can the heat exchanger tin be cut off and with caps on engine end?

You can cut the tin from around the pipes. That would eliminate the heat and just give you a header.

Clay

Like Clay mentions above, you can cut the rusted sheet metal off. I did. But it is a nasty job and I thought about my future tetanus shot if I wasn't careful. But he also mentioned used SS heat exchangers. Your car is the same year as mine and so you would use the early version to just bolt it all back up. I got my early versions for a song because most are trying to get the later version. The ID on the SS tubing is larger than the stock header tubing and it doesn't rust. So maybe run it and keep an eye here. I got mine here and it was painless.

I got in touch with bruce Bedstone. He has some for me. Great parts resource. In the past he outfitted my interior and then some

Cool