Topband: Crossfire phasing

[David Cole]

Hi all - I am puttting in an 80m 4 square and would like some help on the following - Tom  W8JI states he uses 8 directions - and of course the phasing is to the leading vertical at 240 then the 2 centre verticals at 120 and the back at 0 -
When firing off the side in a normal 4 sq we use 0 and 90 - in crossfire do we use 240 and 0 or 120 and 0 - this may seem a silly question  but I am on a big learning curve here.
An explanation on how the phasing on page 11-48 is achieved - I can make it and can understand where the -120 comes from and also the back element - trouble with the back is that if the L/C network puts -120 deg of phasing why is it noted as 0? and where is the 240 from the front coming from - I am really confused  
Next Q in the ON4UN 4th ed Tom states impedence of current forcing feedlines - where-as in calculating the LC network for the rear vertical Tom uses the LAHLUM.XLS for non current forcing? why is this - 
Tom's website under /tx_four_square.htm states 3 advantages four using an artificial transmission line for the rear vertical - he say's " I can easily tweak delay line characteristics with a few adjustments and optimize the array" Q which do you adjust, the delay line going to the 2 centre verticles or the multiple L/C sections going to the rear.
I have permanent current probes in my system which will be installed over the next month - I can measure phase angles accurately using a 2 channel PC based scope - perhaps more will come clear when I actually test out the array.
I would really appreciate any help - I have exchanged emails with ON4UN - but cannot get emails directly to Tom - guess he is a busy guy - like all things when you no the answer its easy - but I have read and read everthing I can find.
Thanks in advance  Dave G3RCQ