Depending on your engine combo (cam, intake...) you might need to go with a lower vacuum rated power valve (4.5 or 5.5) if it's going into a boat.
Have you checked to see how much vacuum your engine is producing at idle? If you have a larger than stock cam there is a good chance the 6.5 power valves will cause a rich condition because of the lower vacuum.
The 6.5 power vavles are a generic "standard" for most street vehicles and will probably have to be adjusted for your application.
Crewcheif is your Holley bitch, as in almost ANY Holley questions. He's on my speed dial....
Personally, on the 3310, I've had better luck at squaring the jets on all corners, leaving the powervalve alone and using the lightest (Yellow) spring in the vacuum actuator (Rolls in play quicker and since there is NO power valve on the secondaries, gives them the head start they need to be seamless, which MIGHT have you jetting down to compensate for this if overly rich). Mind you, I mostly did these on 2-4bbl installs......I beleive larger carbs are really needed on single carb installs, but that is strictly my opinion.
But the Holley rebuild kit will get you going in the right direction. A couple things to check while you are doing it is metering block flatness and flatness of the bowls gasket surfaces as well as the carb body itself. A lot of times they get over tightened and warp and cause weird leaks that lead to symptoms that defy logic. A straightedge is fine, I use a surface plate, but I'm spoiled.
As Crewcheif and a couple others said, these are very different than setting up the carbs for "street" use. We truly only have 3 throttle settings....Idle, WFO, and a specific (Completely dependant on the boat, setup, preference, etc, but will ALWAYS be the same RPM number for that boat once you find what it is.....) mid throttle position for cruising. And THAT is why dialing in on the water, reading your plugs, is so important.
Ray
