Oil Pressure Question

Today when I started my Barracuda up, it seemer like it took a little longer than usual for the oils pressure to come up to the 60 psi that it tends to run at when cold. it also seemed that there was some valvetrain noise for the 2-3 seconds before the pressure came up.

I run an autometer mechanical oil pressure guage, and 10W30 oil.

Once the pressure came up it seemed to quiet back down.

Pressure seemed normal while driving at first, but I was noticing a very quick drop in pressure while braking hard. Pressure would drop down to around 5psi and then would go back up to 25-30 psi which is quite normal for my car to idle at one the oil is warmed up.

Oil pressure is very constant at 60 psi while on the throttle, or cruising speeds. I will drive around a bit more later today and report if I notice any other anomolies.

Any suggestions?