Yeah I matched the threads up and they seem to be the same pitch. Fits as well as the old brass plug on the RRC's. I was so happy when I found it worked stranded 30 miles from home I bought another as a spare the next day at my local O'Reilys. It can go in my other project Disco if I ever get it running.

 

I went to oreilys and bought one yesterday. Still haven't put it in though

 

I can see using a pipe plug or the Dorman plug in an emergency.
But...if your plastic one hasn't blown, you can get the correct brass plug from Rovahfarm for $3.99.
I can't think of any reason to actually plan ahead to use the wrong fitting.

 

Ah I remember reading somewhere that the brass plug wasn't available anymore so didn't know they were out there. I'm pretty sure the Dorman plug is an exact match for the threads. I compared threads and no light can be seen through them when held together. They don't look like a tapered pipe thread. The only minor concern I had was using a plug of a dissimilar metal and possible induced corrosion between the two metals. Hence I put a light coating of anti seize on the threads of mine the next day. I was hoping to find a brass plug in a junkyard one day. But I'll look into the roverfarm one now. Ofcourse some of these tasks get forgotten about until they become an issue.

 

Ahhhhhhhh, wish I had joined this forum 7 years ago when this infamous plug sprung a leak and I paid a tow truck to come ferry me and my Disco back home. I would have much rather paid $1.19 instead of a whopping $100 for the tow. Good info for anyone who is new to the forum.

 

An important point is that every truck with the old plastic plug will eventually have a failure. The heat makes it degrade over time. Please change it before it makes your day in a very steamy manner.

 

Here is a brass one for $3.99
Radiator Brass Plug Ref: ERR4686B
RovahFarm for all your new Land Rover Parts and Accessories

It is the same thread as the DII diff fill plug.

 

That particular brass plug looks to be a tapered pipe thread. I don't think threads in the radiator are NPT. If you put NPT in there the seal may breakdown over time and the threads will be weakened for the correct item. I believe it's designed to seal on the flange at the top of the threads, not on the threads themselves. Best thing is to buy the brass plug designed for it. Or the Steel oil drain plug that fits the threads also. Both ~$4 from the looks of things.

 

Mine was good until I had to disturb it when I had thermostat issues. (95 Disco and probably the original plug). The unscrewing and retightening killed it. A few days after that it popped the top off just like the pics in this thread.

So if it's removed for any reason best to have a metal one ready to go back in.

 

BTW, Impressive miles on your manual Disco. Think that's late enough for R380 right? Not LT77. Gives me hope for mine. 157K now.