OK, quite an extensive follow-up to come here.

the standard paper gasket for the throttle body to plate is a Fel-Pro #60814. I've had trouble finding this available on some sites, but if you Google it there's a few odd-ball sites that still have listings. Google even showed Amazon had a picture on their site, but when you search the part number itself, there are no listings. Strange.

Amazon pic



Now to the O-ring part. I thought I had an extra one or two, but what I had turned out to be an old heater plate set-up I salvaged off an old rig and the old o-ring itself I had removed that is already flattened, but otherwise in good shape:



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Notice in the above image the 3 holes are actually closed off, so no need to worry about allowing an opening on the gasket itself.

Now this gasket is already used, but I still do have a new NOS/OEM kit including an instruction sheet with - you guessed it - part numbers! Sadly, the o-ring itself does not have it's own part number per Mitsubishi, it says it's included with a new heat plate. a cursory check of a few Mitsu part sites show it's still available for around $75 for this hunk of aluminum with a new o-ring. Strangely, I could not get any hits for the entire kit part number.














At $75 to get a new o-ring (with a new plate) - that's one expensive gasket!

I do work for a gasket maker and with time it might be possible to ask my prototype shop to make several dozen, but it becomes a bit sketchy when attempting to make a gasket that might still have a patent on the design. And being a singular model year design, I'm sure there's not much demand for it anyway to make this all worthwhile.

As for my NOS kit - I might be interested in selling it, but knowing it's rarity now and how difficult it is to get that damn o-ring, it might have to be one heck of an offer to let it go.

Permatex gasket maker might do just as well - just be sure not to use too much where it creates a gap in between the mounting surfaces causing it to "float".

Jim