Aha, I thought your name was Steve as that's what Andrew called you!
I'm presuming that I can use a T-piece (which I may attempt to make by braising together the copper heater matrix pipes, or not) which will allow flow through the heater matrix pipes at the back of the engine. The hose on the third connection will run up to the expansion bottle mounted on the bulk head the other connection from the bottle will then run to the rad. Have you sorted a blank for the rad thermoswitch?
I want to use a big fan for when I go turbo. Maybe the 14" one will fit
ok?