differences in electric fuel pumps.

i hope this isnt a newb quetion, so dont laugh....im gonna get a electric fuel pump. im running the mechanical right now with my weber an its hard to start. thinking to much fuel pressure. anyways, im looking at different pumps an there are some that are 12v rotary and 6v rotary vane?? which one of the two do i need? most i have looked at are 12v, but a few of the carter 4070 knockoffs are 6v rotary vane.

12 volt is what your truck runs. But you need to run about a maximum of 5 psi. As for the hard to start, that is most likely a choke issue.