Side exit exhaust
They're Dynomax Super Turbo #17676, which are 2 1/2". For some reason they also outflow the more standard offset in/center out muffler they make in the same size...Says 520cfm on their website. They're also $61.95 ea.
Its hard to see but I'm holding them up in the back in order to not crack the pipes. I had to customize those cheap parts store holders a little bit though...They've got some steel "extensions" welded to them.