Mustang MonthlyHow To Tech Qa
Magnum 500 Wheels, Radio Ground Strap Direction, and more Vintage Mustang Concours Technical Questions Answered
Magnum 500 Wheels
I have a question on 1969 Mustang wheels. In MCA concours classes, do the judges accept Magnum 500 wheels as a dealer option? They look great and seem to be very popular today. If Magnum 500 wheels are not considered concours correct, how big of a deduction are they?
Magnum 500 wheels were not an option in 1969 or 1970 on the Mach 1 Mustang. Therefore, they are not concours correct in any MCA Concours Classes. All 1969-1970 Mach 1 Mustangs had 14-inch tires and wheels. The only Magnum 500 wheels offered in 1969-1970 were 15x7 Boss Magnums. If you use 15x7 Magnums, you would also have the incorrect tire size, which is another deduction. My advice is use correct Mach1 tires and wheels for MCA events. I admit Magnum 500s look great on all 1969-1970 Mustangs, but they are not concours correct on the Mach 1.
Radio Ground Strap Direction
I have a 1970 Boss 302 question. My car is an April 1970 Metuchen-built car. The radio ground strap on the cowl points towards the windshield. I have been told it is on backwards by more than one MCA judge. I have a picture of the cowl area before the restoration. I looked at a very nice unrestored 1970 Mach 1 recently that was a May-built Metuchen car, which had the ground strap also facing the windshield. Does it matter the direction of the strap to be concours correct?
Typically, the radio ground strap is mounted facing the engine compartment on most 1969-1970 Mustangs built at the Dearborn assembly plant. However, 1970 Metuchen-built Mustangs, including the 1970 Boss 302, often had them facing the windshield. I would not change your strap if you believe your original photo indicates what you replicated during the restoration. I have two unrestored Metuchen 1970 Mustangs with ground straps facing the windshield.
Autolite Accelerator Pump
As a reader of your column for many years, you’ve helped me a number of times on my 1967 Mustang! The accelerator pump diaphragm and gasket is leaking gasoline onto the manifold. I’ve carefully cleaned the diaphragm and gasket and carburetor housings, and tried Permatex No. 2—with no luck. Please advise a sealant that will work! There used to be a kit for the Autolite 2100 to include the diaphragm and gasket, but I don't see them anymore. Once again, thank you for all your help via your columns. I wished it was two pages and not only one!
NAPA sells a quality pump gasket that we use for Autolite carburetor rebuilds. No sealer is used for the installation, but make sure your carburetor housings are flat. If you find the parts are warped, corroded, or pitted, then nothing will seal it. The accelerator pump diaphragm from NAPA is part number 2-4295.
Backup Lamp Gaskets
I recently found a pair of C7ZZ-15533-A 1967-1970 backup lamp gaskets at the Carlisle swap meet. They are new in Ford wrappers, but they are black. I always thought they were gray? Did Ford use black as well as gray?
In the ’80s Ford serviced the C7ZZ-15533-A gasket with black, rather than gray. The 1965-1966 Mustang backup light gaskets were always black. The same vendor made both the 1965-1966 and the 1967-1970 gaskets, and apparently, made them all black as service parts in the ’80s. Real 1967-1970 gray gaskets are a rare find today!