Mustang MonthlyHow To Tech Qa
Vintage Tech Advice March 2013 - Beyond the Basics
I own a '67 Mustang and I'm trying to figure out if the carburetor on the 289 is original. It's an Autolite/Motorcraft 4300 but I'm told that the 289s came with a 4100. Can you tell me if the 4300 was stock, special order, or if someone installed it after the car was purchased? The installation looks factory and not an add-on by a back-yard mechanic.
The Autolite 4300 four-barrel carburetor was indeed used on most '67 A-code 289 engines. It was a new design to replace the older 4100 as new emission regulations were beginning to be implemented. However, the 4100 was still used on the '67 289 High Performance engine.
The '67 factory Shop Manual has an excellent section about fuel systems and can serve as a resource in many situations. The carburetor specs and part numbers are clearly listed. I recommend a Shop Manual for all vintage Mustang owners. They're available from most Mustang parts vendors.
Upgrade to 5-Lug
I need to find a donor car so I can change from 4-lug to 5-lug rear axles on my '65 six-cylinder Mustang to match the front disc brake set-up I recently installed. Can I use a set of axles from a junkyard Mustang?
Six-cylinder Mustangs with their 4-lug wheel bolt pattern also used 9-inch diameter brake assemblies and a small 7¼-inch ring gear rear axle, while V-8 cars had the 5-lug bolt pattern, 10-inch brakes, and 8-inch ring gear axle. The 5-lug axles will not bolt into the smaller six-cylinder rear end, therefore a complete rear axle swap will be necessary.
The rear axle from a '64½-'66 V-8 Mustang is a direct bolt-in replacement for the six-cylinder unit, providing you with a stronger ring gear, 5-lug wheel bolt pattern, and larger drum brakes to complement your new front discs. Be certain to locate an early car axle; the '67 and later axles are wider and may create tire clearance issues. The universal joints may also be different so the V-8 driveshaft that matches the rear axle may also be needed.
Trunk Latch Dilemma
The trunk on my '67 Mustang convertible no longer opens when you turn the trunk key. As I recall, there is a metal tab between the lock cylinder and the latch, and I suspect this tab has come out. What is the easiest way to remedy this? Drill the lock or try to go through the back seat?
Ottawa, Ontario, Canada
This is a tough issue because there is no easy way to enter the trunk area from behind the rear seat on a convertible. Mustang convertibles have reinforcement behind the rear seat, preventing anyone from fitting into the trunk. It is open enough, however, to work from the rear seat area to observe the trunk latch and rotate it with a very long screwdriver. Unfastening the vinyl well may provide additional access.
Drilling the lock will only remove the center, or tumbler, portion of the lock assembly. The rest of the lock cylinder will remain in place. This method is used when the lock will not turn, such as with a lost or broken key, but will not help if the extension between the lock and trunk latch has become disconnected.
I have a '65 Mustang fastback that does not have the door tag. The VIN number is on the fender, but as you know this provides limited information about the car. I did locate the tag on the transmission, but I cannot locate any information online to decipher these numbers. I was hoping you could point me in the right direction.
Via the Internet
Much of the information included on a door tag can be figured out, with the exception of the date code and DSO. There are many publications that include, some specifically, data plate code information that can be used for reference. As an example, a fastback with standard interior is a body code 63A. Interior, body, transmission, and axle codes can usually be easily identified. The rear axle has a tag on it, similar to the transmission, which can also be deciphered. Reproduction code tags are available with your supplied information from most Mustang parts vendors.
The build date and the district the car was ordered from will have to be estimated. Date codes on original parts will give hints to the build date. Engine castings, such as the intake manifold, will have a cast date code, such as 5B12: 5=1965, B=February, 12=12th day. Body parts are stamped with the month/day/stamping plant (but not the year), such as “9302D” for September 30, second shift, Dearborn plant. Most parts have a date code although they may differ from part to part. A good decoder book will explain them in detail. The car was built after the individual parts, so the build date is usually a few weeks after most parts.
An old owner's manual may give a clue to the area the car was purchased from or any previous owner history may help to figure out the ordering district. If the car's “build sheet,” as used on the assembly line, can be found (taped to underdash wire harnesses, stuck between seat springs, or tucked underneath the carpet), the end date is listed. However, build sheets rarely survived.
Let us hear from you. Send your '65-'73 Mustang questions to: Beyond Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to firstname.lastname@example.org.