There are two main branches in the decay from 8Be* to 8Be(g.s.). The branch ratio of gamma to e+e- is about 10^3.
Related Material 2 at the bottom of this page.
8Be Decay
More information about 8Be, click here. (www.nndc.bnl.gov/nudat2/getdataset.jsp?nucleus=8BE&unc=nds)