I have been trying to tune my Holley carb for a while now. My dad had passed away and had given his 1967 Fastback with a 302 bored over to a 347 to me. He always said that the carb was "too big" for the engine so it ran rich? As I am trying to tweak the fuel levels in the float bowl assemblies as well as the 4 corner idle screws and STILL get an RPM of around 600 to 700, online, there are 2 different opinions on fuel levels for this carb. Some say, while running, it needs to barely be visible at the bottom of the site holes. Others are saying it needs to be at the middle of the site holes where there are two "marks" so to speak. I figured, the first step to tuning this carb to the best of its ability with this motor, I need to make sure the fuel level and bowls are set correctly, then adjust the 4 corner idle screws, THEN adjust the RPM's while car is in D and brake is applied. (3 speed Auto). Is this the best way to do so? Also, what are your thoughts on the fuel level and float bowl adjustment in these carbs? Down the road, I will be wanting to replace the gaskets on both metering blocks as well as MAYBE jetting it down. If I do that, where would I start on getting the correct gaskets and/or floats for that carb? Like I said, I BELIEVE its a 4150 Double Pumper Super Street series. Cant find any numbers on it but have looked on Holleys website for pictures that look like the one I have. Any information would be GREATLY appriciated!!! Thanks!