Southwestern Bell Corp.'s earnings were up 2.4% to $1.05 billion for 1987, compared to 1986. Revenue totaled $8 billion, up 1.3% from the prior year. The St. Louis-based company said the results were held down by the cost of acquiring certain cellular and paging properties from Metromedia Co. U S West's net rose 8.8% to $1.006 billion for 1987, compared to the previous year. Revenue totaled $8.445 billion, up 1.6% from 1986. The Denver firm attributed the results to the performance of its telephone companies.