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| Antenna Nut - 68 Firebird |
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| OK, so it's trivial. But when I was doing some work on the fender of my 68, I decided to replace the beat up factory original antenna mounting nut. See "2" in the adjacent drawing. GM part number 3863499 (Applies to 67 and 68 Firebird front and rear mounted antennas) |
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| I ordered the repro nut from a major restoration parts vendor and found that the threads were "squared off" instead of "sharp" so the ability to grasp the antenna body was poor.* Second, the hole at the top of the nut is 5/8" instead of about 17/32". When placed on the factory original antenna body (which has a 1/2" black plastic filler that the nut fits around), a gap existed between nut and the antenna body. Besides being incorrect and unsightly, it would collect water and dirt. The repro nut is presented as an "Original Equipment Reproduction" GM Restoration Part. In Checking with a couple other major 1st Gen. vendors, it appears that this part must be the one offered by multiple vendors. I located a supplier of OEM antenna parts where I purchased an exact replacement. (Email me at [email protected] if you would like his address. |
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| Using a felt tip marker and paper I took an impression stamping of the original part threads. |
| The repro part thread is actually concave. The narrower of the gaps are the surface on the top of the threads. |
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| NOS |
| Factory Orig |
| Repro |
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| NOS |
| Factory Orig |
| Repro |
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| Note the larger hole size in the repro nut |
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| * Note that the vendor I purchased the repro part from checked several additional nuts on the shelf and he did find one with better threads. Because of the incorrect hole size; however, I did not opt to have them send it to me as a replacement. |
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| "Now that looks great!" Replacing the old shabby antenna mounting nut and cleaning and polishing the other factory original parts yields a beautiful assembly. The NOS nut grabbed the body during assembly perfectly. The repro would not. The gap between the black plastic body and nut is minimal. The repro was poor.. |
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| To the right is the full factory AM, front mount antenna with new NOS mounting nut. |