Ford used two different "Holley type 4000" carburetors on the 312 with the blowers.
Neither were made by Holley, but they were sold by Holley.
Good luck on finding any information on these in the Holley books.
Jon.
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
