The benefits of being able to anneal SiC samples for extended periods of time at relatively high temperatures without destroying the surface through the preferential evaporation of Si is demonstrated by comparing 4H-SiC samples implanted with Al or co-implanted with Al and C and annealed at temperatures ranging from 1300 - 1650degreesC. After analyzing the sheet resistance, EPR, RBS, and CL data, we conclude that samples co-implanted with C can more easily be activated because they more readily form electrically active complexes. The previously held belief that the implanted C helps to form more Si vacancies for the Al to occupy is shown to be incorrect as EPR data show that the implanted Al does not occupy Si sites in the SiC lattice.