Oil pressure springs

[87 national]

I have four oil pressure relief springs, red blue yellow and plain. What is the pressure of each? Which is suggested? The only reason i asked is because i have always had like 58 psi cold start pressure now i have been seeing like 45 when i start the car if i rev it up a bit it will raise to 52 and stay there till it warms up.

 

[buickboy]

Go with the yellow (approx 65 Lbs).
Mitch