That is confusing, Iam not familer with this pipe. So do you have dual cooling from your pump? If you do, looks like one line from pump to Nipple D, the other in from pump use a Y fitting and route both ends off this Y to both A Nipples. Then follow the rest of the drawing. G,E,F go to B, C to H with a T over board. Nipples on your head go overboard, 3 pissers total.
Followed the water routing to see if engine would get cooling, pipe would get cooling, stinger would cool water box, looks like we got flow. are any of those nipples water injection spray bars or is it like a B-pipe with fixed spray ports in pipe or no spray ports at all? does your pipe match this pipes fittings? is this a wet pipe or dry pipe?