Remote oil pump - pressure excessive! Any Ideas Why?

Hiya all,

I have a 3.5L Rover V8 engine with dry sump setup and external oil pump.

It all works but oil pressure is about 80psi at tickover and when driving it goes just off the scale at over 90psi.

This is a tad high as it should be around 50 - 60psi max, and I am worried abouit blowing oil seals. Pics Below.

So I have a few questions:

It it possible to over fill the dry sump resevoir which would result in pressure being too high?

Do external oil pumps have internal pressure relief valves fitted to stop them over pressuring?

Is there any way I can reduce the pressure?

There is a round plate on the back of the oil pump but I have no idea whats behind it, any one have any ideas?

http://www.btinternet.com/~urban.fx/Pump1.jpg[/url]

http://www.btinternet.com/~urban.fx/Pump2.jpg[/url]

Thanks for your help,

Lawrence