Well, are you using a t-case lowering kit or do you have an SYE etc. installed? If you are using the tcase lowering kit, you will need an adapter for the linkage. If you have an SYE installed and are not using the tcase lowering kit, you should not need the adapter, and probably just need to adjust your linkage (unless you have a body lift also, which would need the adapter then as well).
At least that's what I think, others will know better I'm sure