Shifts slow

Just got finished putting a head on and now my car shifts slow and makes a clunking sound.
when in park the RPMs seem normal and revs real good but when in gear it slow reving and lacks power also.
did I un-hook something going to the tranny ??
or what could it be ??
All of you have been great getting me this far but now I need a bit of help again,:frown: Im lost...

I dont know if your tranny would be the same as the one in my 92, but there are two connectors on the front of my transmission. The little one is for the transmission temperature sender, the larger one is for the input shaft speed sensor (aka turbine speed sensor). There is one 'rectangular' connector atop the transmission, having to do with controlling the solenoids in the valve body. On the rear side of the transmission, where the shifter lever is controlled by the shifter cable are 3 connectors. One has only a single wire. One has 2 wires, and I think is for the neutral safety switch. The other connectors has about 6 wires, and I have idea what they do. The speed sensor is located on the same backside of the transmission, and tells the PCM how fast the axles are spinning.
Is the Check Engine Light coming on? It might have useful info. The manual for my 92 Saturn automatic transaxle has over 100 pages about the tranny related trouble codes that might show up. So you might want to get the 'trouble codes' checked.