We explore the electronic structure in the heavily overdoped regime of the single-layer cuprate superconductor Bi1.74 Pb0.38 Sr1.88 Cu O6+δ. We found that the nodal quasiparticle behavior is dominated mostly by phonons, while the antinodal quasiparticle line shape is dominated by spin fluctuations. Moreover, while long range spin fluctuations diminish at very high doping, the local magnetic fluctuations still dominate the quasiparticle dispersion, and the system exhibits a strange metal behavior in the entire overdoped regime.