Thermostat housing / water outlet

[Sabesimpson]

Originally Posted by BobBray

I found this one for an older Pontiac, but the outlet is more vertical:

https://www.rockauto.com/en/moreinfo...10337&jsn=1638

Hi! What vehicle did you look up for this?
Thanks.

[James]

Originally Posted by Sabesimpson

Hi! What vehicle did you look up for this?
Thanks.

According to Rock Auto it fit:

PONTIAC ACADIAN 1968-1971
PONTIAC BONNEVILLE 1959-1970
PONTIAC CATALINA 1959-1970
PONTIAC FIREBIRD 1967-1969
PONTIAC GRAND PRIX 1962-1970
PONTIAC GTO 1964-1970
PONTIAC LEMANS 1966-1970
PONTIAC TEMPEST 1961-1970
PONTIAC VENTURA 1960-1961

With a 389 cid or the 400 cid engine.

I don't know if it will fit the GMC V6.

[BobBray]

It all depends on which water crossover you have. The later Pontiac thermostat housing with the wider bolt spacing fits my '67 351.

[Sabesimpson]

Thanks! My cross over has the housing sitting on top at this point if vertical I will try to Mach up a hose. I just need the 3” in center bolt holes

[Sabesimpson]

Here is a shot of the cross over

[Sabesimpson]

Update….. I was able to match up a housing at NPD in Ventura!
Now I found an oil leak coming from up top and running down the top of the bell housing. Smh

[Prowbar]

Originally Posted by Sabesimpson

Update….. I was able to match up a housing at NPD in Ventura!
Now I found an oil leak coming from up top and running down the top of the bell housing. Smh

Good job on the housing.

Some thoughts regarding oil leaks:
1. Rear freeze plug in the camshaft bore... Inaccessible unless you have the motor out. Had this on my old 305E.
2. Valley cover gasket. Easy to replace.

[Sabesimpson]

Thanks! The investigation starts tonight!

[Sabesimpson]

Prowbar,
Investigation complete! You were correct rear freeze plug @ camshaft bore. Oddly, it looks like someone replaced it. Guess i will be pulling the motor sooner then i wanted.

[Prowbar]

Originally Posted by Sabesimpson

Prowbar,
Investigation complete! You were correct rear freeze plug @ camshaft bore. Oddly, it looks like someone replaced it. Guess i will be pulling the motor sooner then i wanted.

Interesting. One check you can do before pulling the engine is to check if the camshaft drain hole is clear.

In the last cam journal, the closest one to the freeze plug, there is a small hole drilled (about .150") longitudinally in the journal to relieve the oil that gets trapped behind the camshaft galley and freeze plug. These can also get clogged with sludge and junk.

Remove the intake manifold and valley cover, then turn the engine so the drain hole is facing upwards. With a small screwdriver or drill bit, you should be able to poke it through.

Having it clogged or at least, close to clogged, build up excessive pressure causing the freeze plug to leak.

Hope this helps.