my 90 loyale has a plug that has been loose for a while and my goofy but didnt know until today, heck i though it was a lifters lol well anyway go too put plug back and know its crossthreaded what should i do?

Its not jammed all the way in is it?

If its just a little bugged up, go to NAPA or parts store and get a chaser. Ive never had to do this on aluminum. But if its stripped you have to put a thread repair kit in. This is no fun.