Any reason a 1982 catalytic Converter won't work on a 1985?

[bramc]

Even though my state no longer requires an emissions inspection, I'm sticking with the ridiculous stock vacuum arrangement for posterity/collectability sake. My catalytic converter glows red hot and my tailpipe is rusted out so it's time to replace it all. Decent muffler shops are telling me the cost of the converter alone is over $500 (and I'm sure it'll be a universal fit). Even though nobody seems willing to install customer-supplied parts, i'm going to go ahead and buy one specific to the car and beg.

I can find 1982 compatible catalytic converters that are much less expensive than 1985. Are there some specific fitment or emissions or performance reasons why those wouldn't work?

Thanks for your help.

[MIPS]

Chemically I don't think there's a difference as I believe the 1982 was a two-way and these days they only sell three-way catalyst. Passthrough volume, operating temperature and fitment should all also be the same. I don't see why they would be iffy about supply your own cat unless it's a combination of installing used/unknown sourced parts and liability under their warranty.
I too like the novelty behind the AIR system even though it includes a bit of extra plumbing but you have to make absolutely sure the carb is correctly tuned and the downstream air line doesn't fail as like you mentioned, yeah the converter on Eagles are famous for getting super hot.

[bramc]

Thanks. I'll go ahead and order and see what happens.

[MIPS]

I double checked the '82 TSM and it seems to imply that the '82 model could fit either the early flat pancake-type pellet converters which even by then were an old design but will also fit the newer monolithic converters.
I've crawled around under my Eagle more than once and unless they changed the transmission hanger bracket for the exhaust you should have space.

[Canoe]

... Even though nobody seems willing to install customer-supplied parts, i'm going to go ahead and buy one specific to the car and beg. ...

Two factors I know of:

• They get their parts at wholesale price and part of their profit is the markup to what customers are charged for the part (and they do have costs associated with managing those accounts, etc.).
• They have a liability and warranty for doing the job - with customer supplied parts:
  - they don't know if that part is correct or quality 
  - they don't have a supplier to go back against if there's a problem or part defect
  So all that is on them - and on their reputation. And they didn't even make any money on the part. More risk, less $.

There was one place we went to for years pre-Covid-19. For most repairs, for the total fee he charged only the retail price of the parts - no labour charge. He and his staff were fast & efficient (servicing taxis was the bulk of their business) and considered the difference between wholesale and retail sufficient revenue. I went there, was flexible on work (service the taxis first - they need to get back on the road and making money), and when I brought parts I wanted used, I understood that he obviously needed to charge what the work was worth. We almost always rounded up for a tip on what he asked for the job. Still way under (often less than half) the usual garage model of book price for labour plus retail for parts.

I had an example of the liability, but in another area. Electrical. I got a deal on some closeout prices for some supplies that were in demand. So I scoooped them up with the intent to resell for a tidy profit. None of the pros wouldn't touch the stuff, even though I could sell to them for less than they were paying. With no supplier to go back on, they'd have been stuck with the liability. Plus no record of chain of supply, so no notice if recalls. Had to take a lot of time to sell to 'retail', with a lot of it given to friends when they had projects...