Torque Converter can't handle the power?
 

I swapped an LQ4 into my Nova, and re-used the th350 off of the 305 I had in it before. The torque converter in it has a TCI sticker on it, so it isn't a stock one, but my car really lacks pep. Is it possible that the converter in it that was meant for 150hp is constantly slipping and not letting the new engine even come close to "locking" (I know it doesn't actually fully lock up)? Or could the villain be not enough ATF in the converter?? I'm trying to spend as little to no money on this auto as possible until I can afford a t56..

Thanks,
-Joe

Any ideas as to why it doesn't feel like it's hooking??