It sounds like that carb just happened to be jetted properly for your particular engine.  That's good.  My Edelbrock 1403 was not performing so well for me last year.  But this year I installed an AFR gauge and used it to tune my carb.  The primary jets were 2 sizes too rich and the secondary jets was 1 size too rich for my engine.  After making these changes, my AFR readings were right in line with the recommendations for idle, cruise, and acceleration.  This year my carb behaved just as you are describing yours.  In addition to tuning the carb, I also added a return line for the fuel, an inline electric pump operated by a momentary switch so I can fill the bowls if needed, and I replaced all the rubber lines with new lines approved for ethanol fuel. And lastly, I routed the fuel line back up the firewall instead of by the waterpump up front.

I think the message is that a carb needs to be clean and well tuned.
 

Last edited by Rufus68 (11/26/2019 8:32 PM)

That carb is a clone of the 4100 Autolite arguably the best carb ever made according to Jon Enyeart
The 4100 I had on my previous engine, a 289, acted the same as your description of the Summit carb.
Congrats!