My 1996 caprice has fuel in the oil and it locked up my engine what are some possible causes?

I think the other two are right, but just for the sake of discussion, you mention there is fuel in the oil...what has lead you to believe this is so? Is the oil over-full? Does is smell strongly of petrol? If you are certain it is fuel in the oil, then my guess would be bad rings, and your engine needs an overhaul. Get a compression check, if compression is good on all cylinders, then check spark...if spark is good on all cylinders, then my theory is bunk.