Min Oil Pressure For Em6 Engine?

[m5040]

What is the min oil pressure before you have to start to worry? I was at a tractor show and a guy was telling me how the 6cyl Mack engines would starve #5 main bearing when the oil pressure starts to get low from a worn engine...... then as I am driving around in my EM6-275 in aw on how much torque it has at 1,100,,,1,000.....900 rpms that I mentally made a connection on what he was telling me about. High torque potential at those low revs when the pressure drops off. Now I am wondering how much truth there is in that statment? My gauge reads about 33psi at 800rpms and doesn't increase until you bring it up to about 1,100 rpm (hot). {and where did the little checkbox go that you could click to e-mail you when somebody responded to your post?}