LR dealers in US don't normally carry the 180 stat. Rovers North and others do. As for radiator, you can eval your in place by warming up truck, then switch off. Temp up/down on the fins in a vertical line should be within 10F if not clogged.

 

I just tested the suspect one and it was operating and fully open around 205-210, partial around 190.
I will be ordering a new 180 t-stat today and maybe a new rad and water pump as well.

 

Your suspect one sounds like an oem standard temp unit, starts to open around 180, and fully open at 205

 

is there a consensus on what a good average temperature reading should be. I am using a scan gauge II.

 

I would say with a factory t-stat ~190-198 highway, 198-204 stop and go around town.

 

great. thanks. i am at 191 highway and 200 stop and go. thats with 180 tstat

 

The I would say your radiator might need a look. This pix is from a member headed down a highway to play in the desert.

 

Those are the temps I am hoping to see :-)
We ordered our 180* t-stat last night and with the July 4th holidays won't be seeing it till the 12th so I have time to do other projects on the truck like checking the rad. This engine is our non-flanged block that we are using to get a smog test done as the Disco has not been off the road for almost 2 years. We have a flanged block ready to be put together but a buddy just finished his deisel conversion and we might go that direction now.

 

hmm your temps are fine, but would think they would be lower with a 180 t-stat.

Is your rad original?

 

Mine is yes