There are 2 basic reasons why out of the box Edelbrocks won't work as direct replacements for an original 426 Street hemi using the other original Street Hemi intake assosiated parts (Air Cleaners, Side Linkage, etc.).

To make original air cleaners work you need the smaller diameter/vintage carb tops, all modern Edelbrocks have the large diameter tops and will not work with vintage air cleaner bases.

To allow the use of all factory progressive linkage parts, throttle cable brackets, return spring set ups, etc. without adding modified or custom made parts you'll need to remove the stock Edelbrock side linkage arms (they are welded on) and replace them with reproduction Street Hemi throttle arms (also welded on). That's just the basics, there's more time and money involved in performing all of this than one might imagine.

While OTB Edelbrocks will bolt on and work on a stock street Hemi intake, it's the small stuff that comes back to haunt you. To accomodate the larger top openings you'd need a custom air cleaner (some steel versions are big bucks) and you'll need at least some mods to the stock progressive linkage setup, etc. Add the price of new Edelbrocks to the cost of the special side linkage and air cleaner required (not all styles are available BTW) and you'll soon find that it's pretty expensive, and when you are done it's still not as stock appearing as simply adding some converted "clone carbs" allowing you to use 100% of the factory air cleaner and other componants.