2005 GTO LS2 Engine Oil Pressure

[HATRK]

Hello. I'm new to this forum and new to forums in general. I have a question regarding engine oil pressure on my 2005 GTO. Hope this is the right place to post this question. If this isn't the right place, please redirect me. Here's the question: What are normal, good oil pressures for my LS2 at the following rpm levels: 750, 1,500, 2,000, 3,000 and 4,000. The car has 122,000 miles and is a 6-speed. I recently had some major engine work done following an SLP oil pump failure and following the work my oil pressure readings have been lower than prior to the work. Car runs fine but the lower readouts are a bit scary. Today I replaced the 5w-30 Royal Purple with 10w-40 Mobil 1. Pressure is now running about 40 psi in 6th gear at 2,000 rpm. My local GM dealer checked his computer and it listed the "minimum" pressure for 2,000 rpm to be 18 psi. It did not list normal or maximum pressures. Just want to make sure I'm not putting too much stress on the engine with the heavier oil. Thanks, in advance, for your input.