Transmission making weird noises at shift

[Appstro]

Anyone know what would cause my transmission to make a sucking shreak when shifting hard from 1st to 2nd? I dropped the pan last weekend to change the leaking gasket on my th350. After it was all bolted back up I added 4 quarts or so of "Wolf's Head" DX III-H/M ATF Automatic Transmission Fluid. The label says "Meets Dexron III -H/Mercon performance requirements". I figured everything was OK until the test drive. I dont recall it doing this before, but I have only had the car for a few months and havent really driven it hard.
A couple other things to consider. 1-the cable coming from the carb has been tightened up a little by me since I installled a new carb. 2-the vacuum lines to the intake have been merged because I didnt have enough openings for all of them on the torker manifold. I didnt think this would affect anything but thought I would mention it. Also these things were done before the noise started... ANY THOUGHTS ON WHAT THIS MIGHT BE CAUSED BY?? What did I do wrong?