GRP II anyone know what this means?

[IL Landowner]

I'm trying to get the correct fuel pump diaphram/rebuild kit for my 1974 mercury 150 hp inline-6. they are saying they have two, one that is listed under my serial number (3913808) but said if I have a GRP II then it would require another kit. You guys have been a huge help so far, can anyone explain this?

 

[Reel Appeal]

Re: GRP II anyone know what this means?

GRPII,most likely means "group 2" if you did not know already.You have a non-integral pump.I do not know what GRPII refers to....