2004R issues !

[newschool72]

I am in the process of debugging a 72 Camaro that I put together from the ground up as a good all around streeter. Im running a LS3 crate engine w a very mild Bullet Racing custom grind, a GMPP dual plane intake and Fast EZ efi, a 2004R trans , 2200 rpm stall and 3.42 gears in the back. It has the Hotchkis TVS springs and sway bars, etc,etc....
I made a trip to the dragstrip to dial in the timing curve on the MSD 6012 box yesterday and started having some issues with the trans. On my first pass I went 12.15 at 112 mph, which was OK, but short on MPH from my expectations by about 3-5 mph. On the trip down the return lane, I knocked it in neutral to let things cool down some, and when I put it back in drive the trans slipped then caught. I down shifted to third and the same thing, and second too. Only when I dropped it in low, did it grab the gear clean. I let it cool down for about 15 mins and drove it down the return lane again, mashing on it pretty hard and it shifted good. I made another pass and heard a loud shrieking noise through 2nd and into third. When I stopped at the timing shack for my time slip, the lady informed me that the starting line tech saw a mild trans fluid leak. I didn't want to oil the track down and mess up the bracket race that was coming up, so I called it quits for the day. I looked under the car and saw a little smoke coming off the headers, but no big leak. I drove it home ( a 40 mile drive) and it seemed to do OK at part throttle. I smelled burning trans fluid at every stop but no smoke rolling out ( very minor leak). I did kick it from a stop once on the way home and it flashed through the RPMs real quickly, like it was slipping, but it hit the gear changes hard.
One more note, I did loose a MPH on the second pass that I heard the shrieking noise. Anyone have a clue what might be going on? I haven't jack the car up yet to try to find the leak. Oh and the 2004R was supposed to be built to hold 550 HP/ 650 FT LBS. Thanks in advance for the insight!