The workhorse of understanding stellar evolution has been in 1D stellar evolution modelling, where simplified prescriptions of physical processes are implemented to evolve a star over its entire lifetime. While stellar evolution modelling has improved over the decades, their results are still limited by uncertainties in the physics due to complex multi-dimensional processes in stellar interiors. To better understand, and hopefully improve some of these uncertainties, we have run 3D hydrodynamic simulations of the final hour of silicon shell convection of a 14M_solar star prior to core-collapse. I will present these results, and compare them to what was found in 1D stellar evolution calculations. I will discuss how the presence of realistic turbulent mixing affects nuclear burning and how choices of convective overshooting in 1D can affect the final structure of the massive star.