I just bought a Holley 750 cfm Vac Sec carb for my boat that has a chevy 350 in it. It runs a little lean a wide open throttle (plugs are bone white with just a hint of light tan). Since there is no secondary metering block on the 750 vac. Secondary carbs (just a pre drilled metering plate), is there any way for me to richen up the mixture at WOT without changing the primary jets? I've heard that raising the float level on the secondary bowl will richen it up a bit at WOT, is that true? Can I just buy a stock metering block from Holley and put in on this carb so that I'll be able to chancge jets on the Secondary side? Thanks for the help.