The T7Design heater is essentially a server cooling radiator & fan, I worked out it used G1/4" straight threads each with a rubber gasket.
I sourced a 45 degree angle and a 1/4" to 5/8" adaptor, mated the two with a little PTFE tape:
It all fits on fine, but I have this feeling the rotating part of the 45º adaptor is going to leak, it just doesn't quite feel tight/solid enough & now I've checked there are versions with no rotating part.. I think it might get changed:
In situ, now I have the 5/8" pipe direct from the heater valve coming in at a nice angle, under the chassis rail, to the heater:
I can't really test for leaks until I'm ready to start the engine, not a lot of point in having coolant just sitting in the system with no pumping/pressurisation.
(see later post this 45º pipe was removed just leaving the hose tail)
(see later post this 45º pipe was removed just leaving the hose tail)