measure the stud that holds the spring down from the top of the nut to the top of stud the extra thread is how much of a spacer you can use and still get a nut back on
next get some round stock from any metal store big enough for the spring retainer to sit on(it's cheap )about 3" diameter have them cut it to the length you measured and drill it out for the stud (it's still cheap)
you will need new caster adjusters (call north shore or sport trucks
a wheel alignment will be mandatory unless you like the vw baja look this will give you about 1 1/2 " of lift which is all you can do without drop brackets due to the alignment limitations you could probably squeek in a slightly taller spring ( i did ) but i got the springs for free which kept me under budget.
if you want to take a look i'm in cloverdale