The oil temps don't scare me....yet. The oil pressure does. Z28 pump is high pressure, not volume right? What weight/type/brand oil are you using?Do you remember your oil clearances?
The pan is not very well baffled for what you are doing. maybe some additional baffles to keep oil outta the crank.
Also, what is the condition & state of tune of the engine? Blow-by can drive oil temps up. Ignition timing can also. I doubt that's the case for you, but I've missed it on my own car so I gotta put it out there. How much total oil? 5 in pan w/filter +3 for accusump + 1 for cooler & lines? you may try lowering the pan level by 1-1.5 quarts. that may keep it out of the crank. Otherwise its time to pull the pan and start welding & shimming pressure springs. It's not staying in the heads is it? Some of the heads have really poor drain back holes, & some head gaskets get in the way too.
Lewis