Yes, the old ones were 600 cfm vacuum secondaries, the new ones are 650 cfm double pumpers. I need the extra fuel at launch. I had the squirters drilled out to .089? On the 600s to get it to leave and not fall on its face. The double pumpers should eliminate that.
I think I could have put stiffer springs in the secondaries to hold them shut a bit longer and muffled the bog, but I think bigger carbs will see an improvement also.