Guys, I am looking to purchase a Holley 750 for my rebuilt Stock 455 with an edelbrock aluminum intake. Can anyone suggest an exact model #? I have looked and there are a few different models so I'm not exactly sure which one is best.

 

You probably want vacuum secondary with el. choke such as this one, link for Holley on Ebay

Have you considered Quick Fuel, QF link

 

I have not tried QF. Are they pretty good carbs?

 

I haven't heard nothing bad about them. It really seems like they are best bang for the buck. I will be running their SS black diamond on my new 455.

 

What are the benefits of a vacuum secondarys over one with manual secodarys

 

Tuning a single pump/ vac vs. a double pumper is a hell of a lot easier. holley has a calculator to help chose a part# for you.

 

Here is a good article that explains the difference between the 2.
IMO vacuum secondary is more forgiving and much better choice for a stock-ish engine in a street driven car.