You are right about the 4100 series Ford carb. I think Holley sold those in the 90's and now Summit makes use of that design. The only downfall the 4010 carb had was when the top plate warped.Thanks for your response. They’re the same carburetor. I’ve been in the carburetor business since high school when I was an apprentice in the mid 90’s. I like to hear what people think and which old carburetor myths are still out there. The 3/8’s float adjustment along with other tuning information is in the tuning literature with every Edelbrock carburetor. It’s not a secret, there’s a 26 page PDF on Edelbrock’s website that would have saved you two weeks. As for the jetting, it all depends on weather the carburetor was manufactured before or after ethanol was added to the fuel. Pre-ethanol carburetors use smaller jets because the fuel had more hydrocarbons. The 600 cfm carburetor seemed slower because of the loss of velocity compared to the 500 cfm carburetor. A 500 cfm carburetor is plenty for a 6,000 rpm 350 street engine. Inadequate air filters are usually the flow restrictions at higher RPM’s. A properly modified and tuned Quadrajet will always be the best choice on a street strip car. Unless you absolutely want a square bore carburetor. Then use a motorcraft 4100. The annular discharge boosters work very well. That’s why Ford wouldn’t sell the patent to Holley until carburetors were obsolete on production cars. I hope this helps and saves you time in the future.