Well since asking this question I have 5.5" RE springs, and a RK long arm kit. Currently Im still running my shocks from the 4.5" RE kit which are 26.5" extended length, which are obviously too short. I may go with the 28.5 from RE, in which another 2 inches doesnt sound very long, but really it is. Also, I could get the "long travel" RK shocks that they sell for the 4" lift which are 29" extended. I think the shocks for the 6.5 were like 32 or so.
Anyway, back to the original question, so instead of any slip issues it looks like Ill have some binding issues....Makes perfect sense.