June 1, 2005

Correct CapI'm addressing this question to you because you are the Mustang Club of America head national judge for authenticity. I have a '66 Mustang hardtop with 28,000 original miles. My car is plain with a 289 2V engine and an automatic transmission as options. The car is authentic under the hood with only a battery and oil-filter change. The original belts, hoses, air filter, and such are still on the car. The tires and the muffler have been replaced.

I have shown this two-owner Mustang several times here in Southern California with many positive comments about its authenticity. However, one item is often questioned. The radiator cap is marked "AC" on top. I don't believe the cap has ever been changed, but several people have told me the radiator cap should be marked either "SMCO" or "Autolite." The AC cap on the car appears to be the same age as the other parts underhood. I am considering a change to one of the others if I can find a nice used one to match the condition of the current cap, especially if you tell me the AC cap is incorrect for my car. I know you like unrestored cars and have sound knowledge about correct factory parts.Daryl GreenSan Diego, CA

Your '66 Mustang sounds like a great find. Your AC cap is probably correct and original for your Mustang. AC was a major supplier for General Motors in the '60s. For this reason, most people don't recognize the fact that AC also made radiator caps for Ford products, including the '66 Mustang. Based on my experience with the AC radiator cap on the '66 Mustang, I believe this cap was an assembly line unit only. It was not serviced by Ford's Parts and Service Division.

The most common '66 Mustang radiator cap was made by Stant Manufacturing Company, thus the reason for SMCO stamped in the top of those caps.

If your AC cap has the number RC-6 stamped along with RC, it is a genuine '66 Mustang radiator cap (see photo above). If the number is not present or is different, your AC radiator cap was probably replaced early in the car's life at a service station or parts store.

Boss ID PaintI have a couple of Boss 302 detailing questions. I would like to know the color and location of the driveshaft paint stripes on a '70 Boss 302 Mustang. I can see the outline where the original stripes were located on the driveshaft, but can't determine the colors. I do not have a buildsheet for the car. Also, what colors go on the front and rear sway bars and where should they be placed? Bob CookStreamwood, IL

The '69-'70 Boss 302 driveshaft had three identification stripes near the center of the shaft. Front to rear, the approximately 1 1/2-inch-wide stripes were one lavender and a pair of blue, with approximately 3 inches between the stripes. This information is on the buildsheet for Driveshaft I.D. as "BU, BU, LA," for blue, blue, and lavender.

The front sway bar has green paint on the left (driver) side of the bar where the link kit attaches to the bar. Both link-kit bolts have green paint also. The bolt sleeves often had green paint on them as well.

At Liberty With ValanceI have a question about the '69-'70 Mustang front valance paint. What is the correct finish for the backside of the valance? There seems to be a mixed consensus on body color or red oxide primer. I'm about six weeks away from final paint on my Boss 302 and would like to get it right.Tommy MasonLoudon, TN