The South Coast Air Quality Management District board has named James Lents as acting executive officer after the announcement by Executive Officer Jeb Stuart that he would resign effective May 3. Lents, 42, who was hired in February by Stuart as his chief deputy at $72,000 a year, is among those competing for permanent appointment to Stuart's job. Before joining the district staff, Lents directed Colorado's air pollution control program. The board is expected to take several months to fill Stuart's post after a nationwide search. Stuart, 63, who earns $80,000 a year, said he will become a private consultant representing clients with business before the district.