chain links per inch

[BigOkie]

I was reading a thread just lately that said how many links you would have to add for ever inch you extended the swingarm. I can't find it now no matter what I put in search.
I got a +2 swingarm so I need a longer chain. I just bought new sprockets and z-ring chain in stock size. How many links do I need in a new chain? And wouldn't the like new sprockets be ok with a new chain?
I saw a 520x104 link o-ring chain on ebay. Is that long enough?

 

[bones]

well the 89+ warriors use 98 link and 87-88 use 100 link chain cuz of the 1" extra length

so with a plus 2 id go 102 link

 

[alex456123]

Its 2 links per inch.