[Tom Vaught]

Today, I am going to talk a bit about "Holley Carburetor Information". When I worked for Holley we had a book called the "Illustrated Parts & Specs Manual".
Holley Carburetion No 36-51 (Rev 2)
Retain 36-51 (Rev 1) for some discontinued models. 1975

Contents:
Numerical Parts List
Adjustments and Specifications
Service Parts List
T.V. (Typical View) and Carburetor Illustrations.
The Price was 43.00 to have it printed and Holley/ Colt Industries Carburetor Division PO Box 749, Warren, Michigan 48090 was the publisher. The manual was red/orange in color and everyone called it "The Red Book"

It had info on things like
"How to do a 'Dry Float Setting' (Fuel Bowl Inverted)
Automatic Choke Settings
Air Vent Valve Clearance (pre-emissions setting)
Choke Qualifying Dimensions
Float Drop settings
Accelerator Pump Adjustments (even in 1975, Holley said go to WOT, push the diaphragm lever down, and measure the clearance. (To make sure the pump diaphragm was never torn and a gas leak could happen.)
Fuel Pressure settings to the carburetor (and a lot more info).

Holley also came out with Service Guides and one of my bosses (Mike Urich) wrote several Books called HOLLEY CARBURETORS over the years. Can still find those in print.

So then you get into a secton of the book called:
"Variable Specifications and Parts"

The List Numbers start at 388-6AS carb (which was a White 3000 Series 150A Engine Carburetor).
The last List Number in this 1975 book is a List # R-7514-A Carburetor (for a 1975 Mustang 2.3L Engine Auto Trans).

That being said on page 121 of the book we have the FIRST HOLLEY DOUBLE PUMPER CARB LISTED: R-4776AAA A/M 600 CFM W/Dual Diaph Pump It gives the Illustration Page for the carburetor 34-1 It also gives the part numbers for the different carb parts. 34-1 Illustration starts on page 241 and goes to page 243 (with two illustrations
The first Part on the list is the Choke Plate and 205 parts later is the Choke Thermostat lever.

I bring this up because each carb series part (4150) kept that illustration number. So Illustration Part # 101 is "Main Metering Body and Plugs Assy - Primary" and Part # 102 is "Main Metering Body and Plugs Assy - Secondary".

So now we know that the Metering Block Numbers for a 4150 style carb will always be basic Part Number "101 & 102".

So all that being written, FIRST HOLLEY DOUBLE PUMPER CARB LISTED: R-4776AAA A/M 600 CFM W/Dual Diaph Pump will have stamped on the Primary Metering Block #4776 and 5882A and the Secondary Metering Block #4776 and 6502A on the top (right side) of the metering block. So with the book I can identify any Holley Double Pumper carb (even if the choke tower is milled off and the guy is claiming it is a 800 cfm carb (not a 600 cfm carb) by reading the metering block numbers. The Carb Throttle Plate assy will be stamped with 4790A somewhere on the base.

So that is how the basic Holley Parts Identification system works.

Tom V.

ps I have the 1975 Book, the 1982 Book, and the 1989 Book which pretty much covers all of the Good Holley Performance carb part numbers before the HP series carbs. (The 1989 Book has all of the older Dominator Carb Numbers in it).

SO IT REALLY HELPS BE A HOLLEY CARB "EXPERT" WHEN YOU HAVE THE CORRECT INFO IN A DISCUSSION
(and actually worked for the people and know where to get the actual specs).