Broken bellhousing

I just put a rebuilt engine in my truck, got it back from the mechanic yesterday, and now this! I have a big piece missing from my bell housing covering the torque converter! I think it should be replaced asap, but I don't have the money right now to do it. Should I drive with the piece missing? I know a lot of these have a drain plug there that is missing, but this is about twice the size of the plug hole I have seen in other pictures.