I'm taking the feed direct from the thermostat elbow, hopefully slightly down hill to the heater which I hope will avoid airlocks.
The take off is a 5/8" fitting, black stuff is my gasket material. Drilled through the silicone hose with a step drill then cleaned up with a knife:
In situe;
This is as far round as I can get it leaving enough hose to attach to the thermostat casting. Alternatively I could go vertically down - we'll see how well it works with hot coolant flowing. The pipe is 1/2" to fit the heater matrix; it seems to just stretch to 5/8" - so for now I'm avoiding any pipe resizing fittings:
Not too bad a route, just shy of the battery location; no joins the pipe goes straight through the grommet in the firewall and on to the heater.
The cold return will go under the battery tray panel, via a cut-off valve, and follow the underside of the round chassis tube towards the water pump.
