Thermostat housing

[JKZ27]

In 69, were the small block thermostat housings aluminum or cast iron? The one on my L48 is cast iron. It appears original but I'm not sure if its correct. Thanks.

John

[Jonesy]

aluminum. Yours is not the original one.

[rich69rs]

#3877660 was very common on small block and as Jonsey has indicated it is aluminum.  Part Number is on the top of the neck.

Not sure if there were other part numbers for '69 small block thermostat housing applications.

See attached pics.

[Jerry@CHP]

Have also seen them with the # around the base too.  People were paying big $$ for them thinking that the base number was correct.  They both are correct.  Funny how the rumors get started.

JM

[JohnZ]

I have the print for the 660 housing, and it shows the part number location as "optional", which means the supplier can put it wherever he likes, with Engineering approval. In the Corvette restoration community, it's generally accepted that housings made through 1968-69 have the part number cast on the base flange, and those after that have it cast on the outlet neck. The current reproduction has it on the outlet neck.

[rich69rs]

Jerry / John,

Thanks for the additional info.  Didn't know about the base being an additional location for the part number.  It just amazes me how much info. and knowledge that the people who participate in this forum have.  What really makes it for me - learning something new everyday.

Richard

[JKZ27]

Thanks guys, My iron housing looks and works so good I almost overlooked it. Did the aluminum housings leak and/or rot pretty often? Possibly the reason mine was likely replaced in the 70s by the 2nd owner.

John

[JohnZ]

The original 660 housings suffered from electrolytic corrosion both at the base and on the neck, which is why you see lots of them on eBay with heavy pitting; the earlier 660's with the part number cast into the base flange (which the Corvette guys are always after) are hard to come by in good condition.