[MOTORHEAD]

Tom: I do have the FE expansion tank, with a 13# cap, which after some stop & go traffic will open and purge coolant, so at the end of a long cruise I've lost a bunch of coolant. Dave K. told me the original radiators they used would not take a lot of pressure, don't go over 13#.
So I figure if I have a closed system, it will get sucked back in, so no lost coolant.
From your pics it looks like your tank is in the header area . I have room there, but figured that was way too hot, plus I thought if I keep the tank higher, it would be easier
for it to flow back in as the engine cooled.