Oil leak on new 5.0 long block

Over the weekend I installed a new long block in my ’95 F150 4x4 5.0. Everything seemed good. I took it on a 15 mile test drive and when I got back there was oil leaking down around the bell housing. I could see oil on the top of the block and behind the intake. There was a little puddle pooled up near the sensor (knock?) on the passenger rear top of the block. When it’s running while standing still the oil does not leak. I had the thing running at 3,000 rpm for a few minutes and not a drop of oil loss. I took it for a spin about a block away and back and it was leaking? I lost about ¾- 1 quart on the initial 15+ mile spin. Oil is sprayed under the truck back to the spare tire. I cannot imagine that much oil would splash out of the lifter galley if the intake had a leak at the rear gasket? I used a nice ¼” bead of “Right Stuff” instead of the cork ends. The threads were a bit sloppy on the block when inserting the sensor so I put Teflon tape on them and tightened them. I cannot image that much oil would leak around that sensor that is if it has a passage to the oil supply. If it were a leaky valve cover gasket I would assume the oil would leak more on the exhaust and not uphill towards the intake as the oil pools up at the rear of the engine under the valve cover? I’ve tried to get the thing to leak oil as I’m watching but it won’t, only when the hood is shut and I take it for a quick spin. Any ideas? I’m burned out and frustrated after spending over 20 hours on this throughout the weekend.

Thanks,

[addsig]