jmc

The common difference in this arithmetic sequence is $-2-(-8)=6$. The $2000^{\text{th}}$ term is $a+1999d$, and the $2005^{\text{th}}$ term is $a+2004d$, so the positive difference between these two term is $(a+2004d)-(a+1999d)=5d=5\cdot 6=\boxed{30}$.