I have had experience with both Holley and Edelbrock, but I have to admit I prefer the Edelbrock.
In general Holley will provide slightly more HP but not be as reliable
The Edelbrock carb has better drivability, reliability, but you will loose a few HP. From the reading I have done I would place the BG carb on the Holley side but with an definite increase in quality.
The biggest problem most people have is the correct carb jetting. Detailed set-up and tuning for the Edelbrock is available on my website.
