Thermostat housing P/N

[Dave Stafford]

Are the thermostat housings still available through GM for the '67 400hp 427?
If not, who's a good source for correct one?
Thanks is advance
Dave Stafford

[Joe L.]

Re: Thermostat housing P/N

Dave-----

Yes, the thermostat housing, GM #3877660, is still available from GM. However, current versions are configured a little different than the originals. Functionally, they're the same, but appearance-wise there are a few differences that are "easily detectable".

I think that Paragon manufactures a reproduction which is very close to the original. However, your best bet is to go peruse your local self-service wrecking yard. These housings were used on a wide array of Chevrolet V-8 engines from about 1966 onward. Look for one off of a 66-73, or so, Chevrolet V-8 and you will get one correctly configured. Some may suffer from serious corrosion damage, but there are plenty of them out there to choose from. There are more than a few good ones. I made a pass one time and "harvested" 4 or 5 excellent ones with no trouble, at all.

[Dave Stafford]

Re: Thermostat housing P/N

Joe, what #'s visibly show on this housing?
Dave

[Joe L.]

Re: Thermostat housing P/N

Dave-----

The GM # 3877660 appears debossed on the the neck of the housing. Original housings had 3 casting depressions located at the base of the housing adjunct to the bolt bosses. There were 2 depressions adjoining the short bolt boss and 1 adjoining the long bolt boss. Current versions of this part lack the depressions.

[Peter L.]

Re: Thermostat housing P/N

Dave/Joe - I'd like to suggest that there are two versions of the original configuration of the 3877660 thermostat housing. The one with the numbers embossed on the neck and the other with the numbers embossed on the back horizonal face of the base. I have the configuration with the numbers on the back horizonal face of the base on a '67 Corvette base motor built Jan '67 and a 327 Chevelle built in May of '66. My Sept built '67 Corvette with base motor has the configuration with the numbers embossed on the neck. I have no reason to believe these are not the original thermostat housing for these engines. Pete

[Joe L.]

Re: Thermostat housing P/N

Pete-----

Yes, I've seen the ones with the part number in the location which you describe, too. During the 66-73 period, the 3877660 outlets were used on a huge number of Chevrolet engines. I'm sure that there were a LOT of molds and, apparently, some had the part number on the neck and some on the base. Since the outlets were installed at the engine plants, I would suppose that it was just the "luck of the draw" as to which style outlet that a particular engine received.