When i turn on the car the oil/clutch light comes on. If the oil pressure is low does anyone know how much a oil pump is for one of these and how hard is it to put in. Also could it just be a crappy sensor???

This engine had some serious oil related problems back then.
Yes it could be a bad sensor.

The oil pump is an easy job as the pump is external-on the front of the engine. The pick up tube is very long. You must fill the pump with vasoline prior to installation. I have NEVER seen another engine where this "vasoline" was required. Good Luck.

You must fill the pump with vasoline prior to installation. I have NEVER seen another engine where this "vasoline" was required. Good Luck.

all engines i know of require the oil pump to be primed with vasoline to prevent a dry startup.

this is out of a saturn FSM - http://www.saturnfans.com/photos/showphoto.php/photo/15857/

Can't you just put some gear oil in?

We always just used a little axle grease. Not a solid plug of vasoline. But that is what the book said so that is what we did.