I have 525's and had to install the merc. water pressure valve on the twins.Had to much pressure at wot.Installed whipples 2 weeks ago and ran the boat at wot on wens and waster pressure was the same as before whipples where installed.I have dual water pickup now and whipples says if you have xz drives with dual water pickup that you need to block off the mid water pick up to make more pressure.I need more water pressure.The reason i'm asking these is cause i want togo to nose cones and maybe upgrade my lowers.What should i do about drives if i upgrade.do i get dual water pick up or just low water pick up in the nose cone.Thanks in advance.

I've heard the same thing about increasing water pressure. I've seen a couple people with this done and asked why. They block off the top 2 or 3 holes on the upper water pickup to prevent sucking in any air. They tapped the holes and used a brass allen head plug.

bingo griff

also the imco lowers make big pressure up and over the 100 mph mark. thee faster than the merc sportmasters as well.