I need to replace my mechanical fuel pump that is located on my raw water pump (GEN V). Will the Holley mechanical fuel pump (HLY-712-454-11) bolt directly on with no mods or problems. Thanks.

I was told that the mechanical arm on the pump is different. When I changed my pumps I bought the Keith Eickert pumps, and they worked really well. You use the top half of your existing pump and put the new lower half on. It gave me the bigger line fittings and larger volume I needed for my upgrades. If you are looking for more volume this is a good unit. Mine is a Gen V also.

Gen 5 or Gen 6 fuel pump, increases your fuel system to an estimated 120 GPH mechanical self-regulated from 6-8 PSI. This pump has a -10 inlet and a -8 outlet.

Has any one replaced their mech fuel pump with an Electric on this set up? Can you just use a block off plate where it mounts to the Sea pump?

Electric is just one more thing to break. They make big enough mech pumps.

I used a gasket and block-off plate when I went to electric fuel pump...

Yes, it will work but not a direct bolt on.
You simply swap out the diaphram assembly by removing the 6 screws (maybe 8; it's been a while) and reuse the armature assembly. You can also rotate it to what ever suits your needs.

Dave

Thanks guys.