Nice Torino! congradulations on the purchase

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IN MY OPION...I'll get shot down by most guys, but if you want a good reliable plug and play carb, get yourself a edelbrock performer or AVS, w/ an electric choke. I've had three cars with that carb and never had any issues, and barely had to tune it. Plus the performance good, I can almost guarantee you'll be happy with it.
Holleys, even the street avenger require tuning, unless you've worked with holleys before, it can be abit frustrating.
600cfm should be fine on stock heads / manifold.
I actually recall an article...i'll try to find it...about the street avenger vs the performer avs, the edelbrock out performed it.