The kit with the UV light pen works well, though you can find them for much less than $120. The breather and oil sender at the front of the engine are notorious for leaks, as are the seals for the cooler. But 1/2 to 3/4 quart is an awful lot of oil, particularly when the car is sitting. Did you overfill after changing the o-rings? The sump and oil tank plugs tight and to spec? New gaskets? Check the valve covers, too. Did you install new gaskets? Are they torqued too much, too little or unevenly?
Oh ... and run it to redline at the track. These engines really are happier when run hard.
