I think holley's are just a pain to tune in. I like my edelbrock 600 on my sbc 350 in my malibu. If anything, a barry grant beats holleys night and day. On that setup, you do not need a DP holley if you decide to go with a holley. DP should only be used really on the track, vacuum secondaries if your going to be driving more on the street.
Project War Bird:
1971 Plymouth Roadrunner
383 4 speed with air conditioning
GY3 Curious yellow
All original