Land Rover 200TDI to Series radiator

I don't know if you know or not but the early 2.25 Land Rover engines came with a skirted thermostat. This worked by the skirt raising up to allow water flow thru the main channels and closing off the bypass as the water heated up. Later thermostats eliminated the skirt.
    This prompted a change in the internal design of the top of the thermostat housings.
Below is an early and late style top. In the early you can see there is room for the skirt to fit.

This also made LR change the location of the inlet in the top of the 200 radiator from the center moving over to the right. Since I kept the Series radiator with the center inlet I wanted to retain my early style housing top. In the pic below you can see the difference in the 2 housings outlets.

So while rebuilding my 200 I realized that I was using mismatched parts. That is I had a non-skirted thermostat in a skirted top housing. Now I'm theorizing that this just made my thermostat rock around in the housing and let it be somewhat ineffective. How much I don't know.

Pondering the fact that I did have overheating issues I decided to see if I could somehow change things to work better. At first I thought yeah, just go buy a 1/4" thick o-ring to fill the gap.

But then,......I thought, hey I might have a bit of hose that would fit there. So back to the hose box and sure enough I found some left over coolant hose from the radiator bottom connection(remember that job?).

It is a piece of Goodyear #62252 hose a molded hose I used the bent part of. The dimensions are OD 2-1/8" x 1-11/16" ID.

I kept the old gasket on the housing to provide a margin of error(and some squish factor) and cut off the required bit with a safety razor,

After removing the old seal I wound up with;

And that meant making a new seal, via the hammer method out of an extra seal from a kit.

That done it was just a matter of putting in the thermostat and bolting it all up.

IHTF it all works!