I'VE TRIED SEVERAL CARBS. EACH ONE GIVING ME A DIFFERENT TOP RPM. THE SMALLEST, AN EDELBROCK 600 CFM GAVE ME ABOUT 6200....A 750 HOLLEY ABOUT 6000 AND NOW THE 850 ABOUT 5800. THIS LEADS ME TO BELIEVE MY FUEL PUMP DOESN'T DELIVER ENOUGH FUEL FOR THE BIGGER CARB. WHAT DO YOU THINK?
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Ok, now youv'e proven that the use of larger carbs are not the way to go. You can try altering fuel feed but don't think there is anything much to gain. Again the cam will not go up where you would want it to wind. Hydraulic lifters will not run in that range and will pump up (hold valves open). This is the limit exclusive of the cam. By running the valves lash on hydraulic lifters loose to the point of just starting to tap, a hundred or two more rpm might be squeezed but thats it. The old Cleveland design has somwhat heavy valve train. The intake valves are large in comparison to most small block V8, 2.04", ex 1.65"
Your work is quite instructional.