The cool-fuel pump for the Merc. Racing 5000 EFI has a different part # (849930T02) then the regular Merc. 502 mpi cool-fuel pump (861156A1). They are absolutely identical in appearance and the rest of the cool-fuel set up is identical. They both use the same fuel pressure regulator part #, set at 42 PSI. Does anybody know if there's any difference in the 2 pumps or is this just a way for Merc. to charge more for "Racing" parts?

same ,but whats a merc racing 5000 efi????

I think your last sentence sum's it up,

It's the new 5000HP Quad turbo nitro motor, wont run on pump gas

Mercrusier Marketing 101: Every 0 Merc adds to the model # allows them to add at least one 0 to the end of the price.
Seriously: are the the same pump?

truthfully I dont know, I have four, 2 MPI and 2 EFI and have came to the same conclusion, they look the same, but is the 500 EFI a bit stronger for the increased HP. IDN

That's what I'm wondering. A 500 efi has larger fuel injectors capable of moving more fuel, but I find it hard to believe it would need to move THAT much more fuel than a regular 502 mpi at similar rpms. WOT for both engines is low 5000's. In addition, the 500 efi also uses a low pressure mechanical fuel pump in front of the cool-fuel system, so I would think that would be there to accommodate a higher fuel flow when needed-