You could fit a bleed nipple into the top hose as that looks like it would be the highest point.
Looking cool nice to see you are cracking on .
Is it just the photo and I am no expert but if your rad is lower than your thermo hosing you will need to fit a expansion bottle ....... (higher) ......or you will end up with a huge air lock problem
Sorry if I am wrong or if I am teaching grandma to suck eggs
Its all good, i've got a expansion tank on the bulkhead. Supplied by the No.4 heater feed. This runs back into the rad overflow (overflow is on the expansion now). This should help keep around No.4 a lot cooler to.