rep2x double drive block base

So i set out to modify the rep2x to make it print pla well with the stock hot ends.
As many people have pointed out the issue with pla in the rep2x is heat traveling too far up the thermal barrier tube since there is no PTFE tube inside. The other issue is the thermal barrier mount is not 100% in contact with the aluminum heat sync block. I decided that I would take advantage of this second problem and design a drive block base that added some active cooling directly to the thermal barrier tubes by routing it down from the top, between the extruders and into the channels in the aluminum block.
After a couple iterations and tests I also decided to add some minor secondary channels that add a small jet of air between the drive gear and the block, that in effect blows any plastic dust that gets stuck in the wheel out if any grinding occurs and helps to keep the metal part of the gear cold to maintain good traction on the filament.

Along with my modified nozzle fan here http://www.thi