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

You raise a good question. The front valance on the '69-'70 Mustang was painted off the car, in a rack with emphasis on coverage of the paint on the front side of the valance. To achieve full coverage of the front, a considerable amount of paint reached the backside of the valance. I would call it moderate body-color overspray. I always see areas of poor coverage on the backside of the rolled edges. You'll often see bare metal with body color overspray around the backside of the edges where primer coverage was also poor. Both red oxide and gray primer were used on the front valance panels at the Dearborn Assembly Plant.

Trailered vs. ThoroughbredI've looked at the Mustang Club of America concours judging rules and have a question about the difference between Trailered Concours and Thoroughbred. The guidelines between the two classes seem to be the same for workmanship, cleanliness, and originality. What is the major difference between the two classes? Why does everyone make such a big deal about the Thoroughbred Class?Name withheld by request

The only real difference between the Trailered Concours Class and the Thoroughbred Class is the authenticity section. In the Thoroughbred Class, all parts must be original Ford, date-coded, and correct for that particular car. In the Trailered Concours Class, most reproduction parts are considered correct.

A top-notch Trailered Concours restoration should have the same quality paint, fit, detail, and cleanliness as a top-notch Thoroughbred restoration. The major difference is original Ford parts versus reproduction parts. The most important criteria for a Thoroughbred restoration are original sheetmetal and no signs of sheetmetal repair or replacement. It would be difficult to start with a rusty car and be competitive in the Thoroughbred Class.

The single most important criteria for a Thoroughbred-quality show car is the paint and body. You can always add original parts (tires, exhaust, and such) months and years after the restoration is complete to move up from Trailered Concours to Thoroughbred. However, you can put all the correct "trick" parts on a Mustang with average paint and body, and you'll always still have an average restoration.

Many restorers overlook the importance of paint and body. Adding reproduction stickers and decals to duplicate a new predelivery vehicle is moot if the workmanship on the rest of the car is substandard.

Boss 351 Headlamps, TiresWe are taking our '71 Boss 351 Mustang to the All-Ford Nationals in Carlisle, Pennsylvania, for the Boss Nationals. The car is original with 42,000 miles and still has the original black exterior paint. The headlights were changed years ago with halogen replacements. What are the correct original-equipment headlights for the '71 Mustang? I think I read somewhere that the '71s did not have the Ford script on them. The only concours reproductions I see have the script. Also, for the '71 Boss 351, are both Goodyear and Firestone brand tires acceptable?Stewart JonesWinchester, VT

The most correct factory headlamp for the '71 Boss 351 is the Tung-Sol brand. The only identification on the front of the lamp are the letters T.S. at the bottom center. This is the only brand of headlamp I've seen on a '71 Dearborn-built Mustang.

The big three headlamp suppliers to Ford during the '65-'73 Mustang era were G.E., Westinghouse, and Tung-Sol. All three date-coded their headlamps on the backside, top center, along with the industry number for that particular lamp.

If you or a judge doubts the authenticity of a particular Mustang, the date code on the back will usually verify the lamp. I always say, "Never say never," but show me some documentation.

As for tires, both Goodyear Polyglas GT and Firestone Wide Ovals are considered concours correct by the Mustang Club of America for the '71 Boss 351, although Firestone was the most common brand used.