That's what US parts books list. OE is fully open at 88C.

 

88C is 190, strange.

 

I got the 180 from autozone.

It didnt have the jiggle valve...is that a big deal?

 

I just drill a hole in them.

I've been using 180F's from O'Reilly. They list, IIRC, a 190F as being for the D1, but I tested them and they aren't fully open until well over 200F.
I bought a Stant 190F at Advance to test and it's not fully open until well over 200F.

I found the dimensional data for the Gates thermostat (again, a 190F) and have attached a file that shows others of very close dimensions that are available as 180F.
Some of the images are blurry as that's the way they are in the Gates catalog.

 

do you guys have a specific part number for the 180 stat , at one Advanced auto parts or auto zone or o riellys ?

Phillip
'96 Disco 153k

 

I bought a small block 350 180 Stanton super stat. I think it listed as a mid 70s. Just drilled a 1/8" hole in the front plate

 

At Auto Zone they list the 180 and a 160 as "alternate temperature" models, but they do stock them.

 

Aside from the six I identified in the pdf, there's this one:
Murray Caps & Stats 15358 - Ultrastat Thermostat | O'Reilly Auto Parts

 

what happens if I use a 160 t stat, in stead of a 180?
woldn't that 20 degrees be better?

Phillip
'96 Disco 153k

 

There are some trade offs. Not enough heat for most in winter. Some web sites believe 160 increases engine wear, but most seem to link back to a single study a very long time ago with different oils, etc. Engine and tranny oils need to be within a certain range of temps for optimal performance, without a doubt. But very cold trucks in the frozen north don't wear out in two winters.

The engine ECU adjust fuel/air mix based on a number of factors, including coolant temp. So ECU might keep sending more fuel to warm up engine, mpg can suffer.

All that is when you are driving at freeway speed. Come to a stop and go traffic, or parked and idle (waiting on SWMBO to return from buying what ever it is that you didn't need); and in this situation you are starting with 160F coolant, but engine heat output, and size of radiator, and air flow of fan(s) will still allow that to creep up, will take a litle longer, but in theory should still get higher. If it gets to 200F now, it may be close to that even with a 160 sat, over a period of time. Clean radiator, good coolant, good fan clutch, working electric fan(s) all play a part at idle temps.

Another thought would be that 160 - 200 swing is greater stress on gaskets than 180-200, etc. Some would say that they notice heat "spikes" when using a 195, and perhaps that isn't the stat, but instead the gasket. So if you don't get hot enough to bother the gasket, that is a plus. However, it may not last long. Many times a used truck will be found to have no thermostat, this is prime evidence that an overheating condition existed in the past that was not solved.

I have run no stat (135 - 145), the 160, the 180, the 195. I've had rad boiled and rodded out. I've replaced and upgraded fan clutch and fan. I've found electric fans wired to run bass ackwards. I've had mud and leaves between rad and condenser. And replaced coolant cap. I like the 180 in mine.

And remember, in the 50's and 60's, it was not uncommon to run a winter and summer thermostat for a lot of guys (grampa's now). And the parts books call for a 180 as oem temp for the Buick Skylark (where our wonder engine came from).