I also strongly suggest a fuel regulator for Edelbrock carbs. If the fuel system checks out, it might be a lean surge caused when running on the cruise circuit of the Eddy carb. I'm running an AVS2 now (chart attached) but the tuning concept is the same. You might need to fatten up the cruise circuit if your carb has a factory electric choke (Model 1406). Edelbrock leaned out the 1406 (600CFM with electric choke) as compared to the 1405 manual choke model. They claim it is calibrated for economy. Here are the factory settings - note smaller mains and fatter rods when vacuum is high:
1405: #1428 (.100") main jets, #1451 (.070" x .047") metering rods.
1406: #1427 (.
098") main jets, #1459 (.
075" x .047") metering rods.
Both have 0.098 secondary jets.
I've read that many have had to change the metering rods and/or springs to improve performance of the 1406. Here's a link to the tuning guide - 1405/1406 starting on page 14.
https://edelbrock-instructions-v1.s3...ning-guide.pdf