M50 Thermostat housing gasket question

[MadJeff]

Never do car maintenance on a holiday weekend, it never works out. =)

I've been chasing down an irritating coolant/overheat problem and went to swap out the thermostat today when I realized my parts guy gave me the wrong gasket. I got on RealOEM and looked at the parts, and it looks like in 05/92 they changed from a paper gasket that fits the housing to a rubber profile gasket. My car is a 10/91 production date, so it's the paper gasket. And of course, I was given the rubber profile gasket.

So now I'm curious, can I use the rubber gasket? It looks like there was no other parts change with the housing or block that would make me think it wouldn't work, and since it was a newer design it must be better, right? =)

Any thoughts? I need to get this back together so I can get to work Tuesday, and after wasting a few hours looking for a paper gasket with no luck I'm leaning towards trying this. On the other hand I really don't want to have to redo it.

[MadJeff]

Well, I answered my own question. After comparing the opening to the rubber gasket there is no way that is working, hole is not the same size. I just went back and looked at the parts listing and there is a part change on the thermostat housing to accommodate the change in gasket.

I guess I'll be figuring out an alternate way to work Tuesday. Too bad I've got my truck torn down as well... =)

[russiankid]

When I did my thermostat I noticed that the thermostat housing itself was flat, but on the head there was a special groove where the thermostat sat, and the rubber gasket went over the thermostat.