While this is about the connecting hoses, it might be of some assistance!
https://www.panteraplace.com/page97.htm
Good luck
Rocky
PS> The other thing I might suggest is putting some stainless steel (exhaust) bungs in the coolant tubes, I put mine about a foot in front of the engine bay. This allows you to completely drain the coolant from the tubes the next time you have to go in there.
Here's some info, and a photo...
Cooling System Drains in Radiator Tubes - Best Approach? | The De Tomaso Forums