Thanks for sharing
You are welcome. I have been repairing and tuning this family of carburetors since the mid 1970s. I am still learning the details that changed over time.
The first time I became aware that there was not "a 3259" but a family of them was in the mid 1980s when a co-worker bought a basket case 1967 GT350. It was a challenge to come up with a carburetor with every part every detail just like the carburetors used on unrestored GT350s in the same time frame. To do so required buying multiple parts carburetors to harvest matching pieces from. The hardest part to find was a main body casting of the matching date and matching casting number. Holley(R) was much like Ford and most mass production companies in that they constantly worked on carburetor assembly revisions to improve performance (example: tweak air fuel ratio curves), lower cost, or address warrantee issues. In this study, five (5) different engineering assemblies between December 2, 1964 (Holley engineering specifications for the original production model released to production operations.) and June 1966 (R-3259-1AAS listed as service replacement for R-3259-1A by June 1966 in Issue 2 of the 1964-66 Holley master listing.)
In my table so far:
Main Body Die Castings = 3
Primary Metering Block Assembly = 2
Secondary Metering Block Assembly = 2
Brass Hex Head Pipe Plugs = 4
Vacuum Secondary Drive Cover Assembly = 3
Secondary Throttle Cancel Link Design = 2
Secondary Throttle Cancel Link Finish = 2 ( the first used, dropped, come back to, dropped again)
Acceleration Pump Cover Casting = 2
Threaded Plug For "Spark" Vacuum Port = 2
My factorials math is very rusty but I believe with just this list one could mix and match versions to build up more than forty (40) assemblies I have no record of Holley ever making. That is exactly what has happened to many carburetors that have gone through a commercial rebuild or restoration. One fellow sent me pictures of his unrestored carburetor before and after a friend of his overhauled it for him. My immediate response to the after rebuild pictures was find out if the rebuilder has already sent the original small parts to the local trash dump. Fortunately the parts had not left the work bench yet and got reunited with the carburetor Holley assembled in 1964. That is not the only time some GT350, Cobra, 427 Cobra, 1967 GT500, Boss 302, or Boss 429 owner has sent me before and after pictures I sent them to go find the rare little pieces now missing in action. Some parts are extremely hard to replace with other original ones.
PS One subject has popped up twice in inquiries to me this year. The issue, finding some transfer tube fittings 100% exactly the same as Holley used 1964-67 in making new carburetors for Ford that are undamaged unmolested (i.e. can be used in a top tier restoration with careful cleaning). In both cases each professionally restored carburetor had non-stock fittings and modern tubing material tubes.
The fitting assembly Holley chose was the Imperial Eastman FLEX(R) "IMPERIAL FLEX PAT'D 1-4" model. It was an industrial and instruments tube fitting and not something custom for Holley. Today Parker Hannifin Corporation offers direct replacement assemblies and Parker 60VL Buna-N Sleeve replacement flareless elastomeric seals.
The exact details of the Imperial Eastman brass nuts in their assemblies changed over time more than once. In the mid 1970s through mid 1980s I would order large selections of small parts in quantity to repair various Shelby and Boss Mustang carburetors from tiny screws up. The first time I ordered "3259" specific parts the fitting assemblies I received were already different than what I ever found on unmolested "3259" carburetors. I still have a couple I bought decades ago. For a long time I robbed the seals out of new assemblies and tossed the brass. Today any Parker Hannifin instrument fitting supplier can obtain new replacement seals for repairs. Side note; the replacement transfer tubes Holley sold by the mid 1970s had different bends in them that the originals I had handled. I still have a new old replacement stock one I purchased decades ago as an example. My solution decades ago was fabricate my own bent tubes myself as required but I have long since run out of 1960s tubing stock.
