My question is, does it make any difference were you mount the coolant reservoir , does it matter if I mount it above the radiator or below the

radiator, or does it need to be level with the radiator ? Thank you Toby

From what I understand no it does'nt.
But! A BIG BUT! ALL is relative to the sealing properties of your reservoir,tubes and spigots.
For eg,if mounted lower,then when the rad cap releases coolant,it will flow down into reservoir,but without adequate sealing,will not draw/suck back up to radiator to replenish.
If mounted higher,will work both ways BUT will eventually all leak out and empty, if not fully sealed thru the system.Make sense?