[Tom Vaught]

Was thinking about the Linkage on the early and later Holley Dominators.

At one time Holley sold a steel plate that was installed under the Dominator carbs so that if (for any reason) the internal secondary linkage came apart it would not go down into the intake/engine head ports.

They built that linkage in a couple of ways on the cam profile. The cam profile (inside the Dominator, see pic #1) somewhat resembled the cam profile on a 660 center squirter carb except it was much smaller in size.

It was held on the throttle shafts by a "Allen Head" threaded bolt (see Pic) . Royal PIA to mess with by a newby messing with carbs.

So that linkage came in three versions:
1 to 1 (all the blades move at the same rate)
Progressive (Similar to the 660 style cam profile)
Soft Progressive (similar to the racer modded 660 style cam profile with a custom opening rate.

Except on a Tunnel Ram type intake designed for Individual Runner applications (Doug Nash IR Intake, no reason to run that linkage.)
Because the carbs might be rated at 1050 cfm each (call it 1000 cfm per carb for easy math) Each IR runner would see a max airflow of 500 cfm. Wham, here comes the 500 cfm of air, then back to sleep, Wham, here comes the 500 cfm of air), then back to sleep, over and over. just like a Weber set-up on a SB Chebby with 48 mm Down Draft Carbs mounted.

Even with the Progressive and soft progressive internal linkage in the Dominators, it was not a full range type of set-up.
Ok for drag racing but not so good on a street car,

The external Dominator linkage is a much better linkage in my opinion, Kind of like a Tri-Power linkage but only two carbs involved (instead of three carbs).

A much better system

I have provided a couple of pics showing internal vs external linkage.

Tom V. Happy Holidays (Snowing in Michigan)