Just took a joyride in the duster

So im shaking right now cause this car is so damn fast, and wanted to see wat you guys think about this. I was driving it ( new stroker motor by the way) and everything looked pretty good to me , one thing is after about 10 mins or so I noticed the oil pressure go down from 75 to about60 and it stayed there for the rest if the drive temp was at around 170 steady the whole time and fuel pressure was at 7.5-8 psi is that oil pressure drop normal after the car reaches operating temp?? Idles perfect at1100 rpms and scares the **** out of me everytime