Hi Simon,
check james KVA pics of fuel pumps and line instalation,I fitted all on the NS sill as per my own GTD ,this leaves OS sill to fit oil cooler with longish pipe runs with no sharp bends,GTD speedo cable run up the OS sill along with battery cable etc so can get a bit busy with fuel lines aswell,I built a CAV acouple of years ago ,had a fuel pump each side but got a bit cramped on ns sill as the AC is also on ns sill.
cheers
John