Hi, from the answers I don't know what to say to help you. On a different thread i said to find the best carb that was responsive and jet to the performance you were needing. I wasn't aware that the cam wasn't already installed, and I am having problems with why you will be running 98 octane for you didn't explain what compression ratio you are running to need that. You also need to possibly rejet to your altitude, for yes it can make a difference in high performance modifications.
I don't know if there would be a right or wrong choice here. I feel what is right or wrong could be how you want the carb to be set up for the mods you are going to be making to the motor- IE - you get a nicely responsive carb that fits good with no vacuum leaks however, there is a tiny more uhmmph that you feel it needs. you will need to fine tune the settings and then if this doesn't do it, you might need to consider tuning the jets one size up or down. all carbs need to be setup to run good. Even brand new out of the box 600 holleys need to be fine tuned or rejetted to make them get the proper A/F ratios. (A/F air fuel)
hope this helps somewhat.
cheers