General reports suggest that you might get a degree or two using the nozzle kit, but that's about it. Possibly more important is the washer that comes with the kit which 1) fully seals the upper chamber, and 2) increases the block's bow a little more. It increases the block's restriction considerably, but you've got a pretty strong pump already.
If you're going to pull the loop apart, and you haven't gotten one yet, you might consider an aftermarket top for that pump, such as
THIS. The DDC-3.2's can benefit a great deal from the top's, since the stock intake is rather restrictive. And if you use the nozzle kit, the top could help offset the reduction in flow.