69 L-36 Thermostat Housing Gasket Configuration

[Greg L.]

Now this might be getting picky but it never hurts to ask.

How much if any of the gasket is exposed and what color should it be? Here is a pick of mine so you can see what I have now. Please let me know if it is correct or what it should look like to be correct.


Note that it is a grey color and is exposed on the fore and aft sides but is even with the housing at the bolt bosses.

Thanks.

Greg Linton
#45455

[Gerard F.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Greg,

Looks like you have the same 660 thermostat housing as my 67 base engine.

Here's the gasket to get:


Got it at a GM dealership. First they tried to sell me on the one size fits all, but I happened to have my old one with me. It has a silicone bead both sides along the edge and fits the 660 perfectly.

Oh, we are out of stock on that one, the mechanics in the shop ran us out, I was told. So I ordered two and waited a week.

Regards,

Jerry Fuccillo
#42179

[Gerard F.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Greg,

Looks like you have the same 660 thermostat housing as my 67 base engine.

Here's the gasket to get:


Got it at a GM dealership. First they tried to sell me on the one size fits all, but I happened to have my old one with me. It has a silicone bead both sides along the edge and fits the 660 perfectly.

Oh, we are out of stock on that one, the mechanics in the shop ran us out, I was told. So I ordered two and waited a week.

Regards,

Jerry Fuccillo
#42179

[Greg L.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Thanks Jerry, I just found out that this housing is actually too early for my 69 because of the location of the numbers so I'll be looking for a correct one now.

Does anyone know when the change was from numbers on the flange to numbers on the neck?

[Greg L.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Thanks Jerry, I just found out that this housing is actually too early for my 69 because of the location of the numbers so I'll be looking for a correct one now.

Does anyone know when the change was from numbers on the flange to numbers on the neck?

[John H.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

That GM thermo housing gasket with the molded-on silicone beads is P/N 10105135.

[John H.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

That GM thermo housing gasket with the molded-on silicone beads is P/N 10105135.

[Joe L.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Jerry------

That one with the silicone bead is DEFINITELY the one to use and it's available, as you found out, under the part number that John mentioned. However, just in case you're thinking that this is the ORIGINAL one for your car, it's not. The original gasket, GM #3701777, didn't have the silicone bead.

After the 3701777 was discontinued, it was replaced by GM #10077105, an almost identical gasket with no silicone bead. For awhile, it was available coincidently with the 10105135, but it's since been WISELY replaced by the 10105135. The "one size fits all" gasket they were trying to sell you was probably some "NOS" GM #10077105 that they still had in stock. Their in-shop mechanics don't want to use these since they don't want "come-backs", so they try to sell them to parts customers instead. Most probably accept them because they don't know about the 10105135.

The nice part about the 10105135 is that you can use it without additional gasket sealer. This prevents the practically inevitable and unsightly "squeeze-out" you get when applying RTV to this gasket to otherwise prevent leaks.

[Joe L.]

Re: 69 L-36 Thermostat Housing Gasket Configuratio

Jerry------

That one with the silicone bead is DEFINITELY the one to use and it's available, as you found out, under the part number that John mentioned. However, just in case you're thinking that this is the ORIGINAL one for your car, it's not. The original gasket, GM #3701777, didn't have the silicone bead.

After the 3701777 was discontinued, it was replaced by GM #10077105, an almost identical gasket with no silicone bead. For awhile, it was available coincidently with the 10105135, but it's since been WISELY replaced by the 10105135. The "one size fits all" gasket they were trying to sell you was probably some "NOS" GM #10077105 that they still had in stock. Their in-shop mechanics don't want to use these since they don't want "come-backs", so they try to sell them to parts customers instead. Most probably accept them because they don't know about the 10105135.

The nice part about the 10105135 is that you can use it without additional gasket sealer. This prevents the practically inevitable and unsightly "squeeze-out" you get when applying RTV to this gasket to otherwise prevent leaks.

[Mark #28455]

Was your thermostat housing "reskinned"?

The surface texture looks different than I expected - was it bead blasted or "reskinned"? Usually the original surface was quite smooth, kinda like the carb castings made with a permanent mold.

Mark

[Mark #28455]

Was your thermostat housing "reskinned"?

The surface texture looks different than I expected - was it bead blasted or "reskinned"? Usually the original surface was quite smooth, kinda like the carb castings made with a permanent mold.

Mark