Thermostat housing, mounting "mod"?

[MLT Lulu]

PO put on a later style thermostat housing, and when I popped it off there's this lovely little cut out on the side of the head. That can't be right, can it? Assuming it's not right, can I get away with it like this?

[Dzimm]

That's normal.  I'd be more concerned with getting a good deal with the damage to the left side of the mating surface.

[MLT Lulu]

It looks pretty solid, though I'm a little curious why they would stamp numbers in a mounting surface like that. Is there something else you're referring to? 

[AZJeff]

Clean the gasket surface with a rotary sand disk or a rotary Scotchbrite pad.  
 

Then use a straightedge to check for any raised surfaces where the numbers are stampeD.   If there are, dress them down CAREFULLY with a file.

 

Use blue RTV sealant on the gasket on both sides when reinstalling.

[MLT Lulu]

Thanks, all. It's back together. That cut out looks like some BS though. 

[Dzimm]

I didn't realize those were stamped numbers, just looked like damage.  As long as it seals you are good.  That cutout is on every 4.0 I've ever seen.  The are slightly different designs on the thermostat housing itself but as far as I know they all work the same.

[mjeff87]

That little cutout feeds coolant to your heater core via the hose connection on the thermostat housing/water neck.  It's normal.

[omega_rugal]

4 hours ago, mjeff87 said:

That little cutout feeds coolant to your heater core via the hose connection on the thermostat housing/water neck.  It's normal.

 

yep, otherwise there won´t be any coolant flowing to the heater core until the thermostat is fully open...

[MLT Lulu]

5 hours ago, mjeff87 said:

That little cutout feeds coolant to your heater core via the hose connection on the thermostat housing/water neck.  It's normal.

After a little looking I saw that.  But it was a later style thermostat housing than the truck would have come with.  Never having seen the cutout before (1st 4.0 I've worked on) I thought they may have modified the head to make the TH work on it.  Glad they didn't.

 

22 hours ago, Dzimm said:

I didn't realize those were stamped numbers, just looked like damage.  As long as it seals you are good.  That cutout is on every 4.0 I've ever seen.  The are slightly different designs on the thermostat housing itself but as far as I know they all work the same.

Definitely #s.  There was also a bit of writing in paint pen on the head, so may not be original?  Sure I'll find out in time.

[Dzimm]

1 hour ago, MLT Lulu said:

Definitely #s.  There was also a bit of writing in paint pen on the head, so may not be original?  Sure I'll find out in time.

More than likely a junkyard replacement then.  Not necessarily a bad thing.