oil leak ,oil pressure

I think I have a rear main seal leaking which has gotten worse.
440 motor. Noticed the pressure going down to around 40 right back to 70 or 80 ,rev a little goes up back to idle & drops to 40,50 or so . It never lost pressure but not acting normal.
Can a rear seal leaking effect pressure like that? I,m thinking yes. Normal for this motor is 80 at startup then around 70 after it warms.

440 30 over ,race motor newly rebuilt . It has been steady until now and the leak has gotten
Worse..... thanks
Author: Skynyrd