Land Rover has an aluminum 5.0 4v (call it a cousin of coyote) and it runs twin crank driven HPFP. Maybe theres a possibility of using some of the internals from those pumps?

 

That might work but would be waaay custom and lots of $$$.

I know a lot of other cars use two cam driven pumps to get more fuel to the engine. From what I've read the HPFP on the EB is bigger than those pumps already. The other option would be to add a second set of port injectors or up the amount of meth he's adding. Using the meth as a fuel source will address some of the fueling requirements.