I built this car and engine in the 80's, The kendigs (preditors) performed better then I expected on the 429 with 30# boost but I never put on holleys to see if it would perform better or not? But on normally aspirated engines Holleys out performed them every time! Many of the 4 wheeler crowd liked the Kendigs because of the rough ride and leaning the truck over big rocks and up steep hills and down (they didn't have the problems of gas in the bowl's running away from the jets or power valves or splashing out the vent tubes like other carbs)!
I personally never liked them! they just never had the snap of a well tuned Holley