Hot end replaced

So I got the printer back up and running. I replaced the hot end, thermister, and resistor. I ran into a compatibility issue though! I ordered a new J-hotend not realizing there could be some major difference. When I took my old extruder off I instantly noticed a difference. My old one is on top. The new one on the bottom....

Notice anything difference besides for color and the resistor stuck in it? How about that nice brass fitting on top of the new one.... It is being used to hold a liner in. In the old extruder there was an open set screw to hold the liner in. Of course this new extruder wont fit my print head...

In this picture you can see the bottom of my print head. The old extruder used to nest nicely in that depression. The new one the fitting is in the way like stated. 

My fix? Drill it out. I just used a big drill bit and kept drilling deeper and deeper until the clearance was correct. I was then able to mount the new extruder. 

When it came time to print I noticed I had to set it at 20° hotter to get good flow? Is this an issue with the new head? Or maybe the thermister is just out of whack compared to the old one? Only time will tell.