Pinion Seal Leak After Rebuild!!?? Help!

[superfly66]

I had help getting my rear end rebuilt by an experience guy. And I dont doubt his abilities but, its slinging oil from the pinion seal...I'm pretty sure. Where else would it come from? Its not coming from the diff. cover. Its slinging all under the bed. I'm going to get under it this weekend. While I had the rear end out I put in all new lowering springs, shocks, front and back and lowering blocks on the rear as well. I watched the guy who rebuilt it put a new pinion seal on it. But its slinging it not dripping...