350 Thermostat housing on a 250?

[Dcdoc45]

I have a 1977 C10 with the 250 I6.
I am putting a new thermostat in, and went to get a gasket from parts store, he said that the gasket was the generic gm water neck gasket. I would like to put a chrome water neck on the engine, to dress it up a little and to get rid of that vacuum actuater in the top of the housing. Since the gasket is the same, can I use an off the shelf chrome 350 water neck?

Thanks
Don

 

[bucket]

Probably fits, just get one that points the same direction and uses the same size hose. Chrome housings usually leak, so there is a downside.

 

[chengny]

The flange section is the same and will right bolt on. What you have to be aware of is the actual neck where the hose attaches. They are all the same OD - that's not the issue.

What is different is the neck's upward angle and how it is indexed. I bought a chrome water outlet once (it was cheap and shiny). When I went to connect it - the hose wanted to kink. Closer inspection revealed that the angle of the neck was way different. Turns out it was for a Corvette - it is still sitting in a cabinet.

 

[Dcdoc45]

yup

Went to a few parts houses today and took my old one in as a comparison.
All of them where index the wrong direction.
The main reason I want a new one, is the vacuum actuator that screwed into the top of the water neck broke. I'm no longer using that system, so I wanted to delete that hole where the actuator went.
I did find out that the water neck from a 1973 250 I6 does not have the hole drilled for the actuator.
So, I may just go with one of those.


Don

 

[chengny]

No need to replace the water outlet. The bores in the housing are just common NPT sizes. Pull your broken TVS out and screw in a 3/4" pipe plug from Home Depot. If you don't like the look of the square tang on the top of the plug, they sell special ones with a recess that accepts an allen wrench (or an upside down bolt).