Im sorting the plumbing on my J15 build and Im trying to sort the header tank.

I understand it needs to be as high as possible but does it matter where it 'plumbs' into the system?

As per the standard car it sits between the water pump/thermostat outlet and the oil cooler (on the oil filter housing) and I'd like to move it to the other side of the oil cooler which routes to the cylinder head water outlet.

Does anyone have any idea if this is OK?

Mine is plumbed up as follows:-

Small pipe at top of header tank to back of cylinder head.

Large pipe at bottom tee'd into heater pipe returning to thermostat housing, I do not have oil cooler fitted as I have moved filter position using race line housing.

From experience the best way to do it is to be a close as Ford intended in the first place. I tried an alternative way and the system air locked and wouldn't open the thermostat.

As soon as I did it like Ford all problems disappeared.