To be more exact: Given two blocks A and B, with heights A < B, but with positions in the blk file (we'll call them pA and pB) pA > pB.
What is the maximum amount of blocks that there could be stored in a blk*.dat file, between pB and pA?
For instance, let's say this is a blk*.dat file:
C D B E F G A H I
We can see here that block A is stored 3 blocks later than B, despite A having a lower height than B. Is there a maximum amount for this value (which in this case is 3)?