I know this is a bit of a stale thread, but i just wanted to throw my carb knowledge out there. My bro in law has the summit carb on his camaro, and it works fine, he don't drive it a lot so i can't really say anything to its daily "driveability" but it did make his car run a lot better than the old worn out holley he had on it.
That stated, i saw some chatter about the summit being a clone of the 4100...its not, it shares some of the design features, like the top plate, no gaskets below the fuel level, everything else is basically a holley 4010 (again, may have been inspired by the 4100). 4100 has an internal vaccum secondary, has different accelerator pump configuration, dual fuel inlets, center hung vs side hung floats, externally adjustable floats... you can't take a single part off the summit carb and put it on an Autolite 4100.
I think the ONLY thing they truly share is booster design. So, its not a clone, just want folks to know that before they go buy one, its more accurate to call it a holley 4010 clone. IN my opinion the 4100 is a better carb, its simpler and just plain works.
Here is a holley 4010