This is a remix with a new blower design so high temp materials can be printed for extended time without overheating the aluminum block on the Mk8 extruder.. It just redirects the air upward above the heating block to cool the stem of the extruder. works up to 260C on long prints with block barely warm.
This blower nozzle prints much better than stock Mk8 because it actively cools the print to stop slow movements on small parts from melting the part or worse yet warping the outer edges up as is so common.
You will need a fan such as this one , mine had no plug so just clip off old and resolder..
It also includes the missing endstop arm to hit the X axis sensor. Straight version is for the modified Zaxis carriage and other is for the stock i3 X - Zcarriage.
Annd print the blower nozzle on the smallest side down rotate 90deg+- ..