It's hard to give a certain figure, but i would expect around 145 to 165 psi, the main thing is that they are even, also when you remove plugs for comp test look for any deposits on electrode, if eng is not burning oil and tuned correctly plugs should be fairly clean and grayish in appearance. You can also see if it is burning oil by revving engine and looking for blue smoke from tail pipe. If the car has been well maintained with reg oil changes then it should be good for another 120,000 miles.