manual fuel pump replacement on 84 454

Any help? My cam lobe wore off my 84 dually crew. Im replacing it with a holley "blue", anyone know the best placement for the pump as i have dual tanks? Also what do i do about the return line after i disconnect the manual pump? I have looked all over the internet and cant find a write or a proper how to. Thanx again, any help is much appreciated.

I mounted my Carter electric pump in the engine compartment, dual tanks work just like before.