It is. I beileve it is due to the smaller primary of the carb. There a pair of 600's. More than enuff if not to much when you add it up in total. It's only a 360 cid engine.
The progressive linkage starts with the rear carb as the main. The butterflies open up about a 1/3rd of the way and then the (front) secondary carb opens up. Being that the linkage is set up the way it is, the secondary carb opens faster and ends at wide open the same time the main (rear) carb does.
In messing with it some, the secondary air door opens up way up the RPM scale. I didn't have the tach hooked up to see where it starts to open, but it was starting to rev high. This engine really only has about a 6500 rpm limit. I'd imagine power falls off before that. Even after I port the intake.
