date code

[RSZ28]

What script date code spark plug wires would be used on May built big block 1965 Belvedere? It seems that a 3rd quarter code would be used for late 64 and early 65 and a 1st quarter code is used for late 65 early 66. Is this correct? Thanks



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[Jerry Hall]

I think you can use first quarter 65 or even 2nd quarter 65. I think spark plug wires went by actual quarters of the year, like seatbelts.

 

[69bfan]

If you are looking to purchase the Lectric Limited Reproduction Plug Wires, they only offer them in either a first or third quarter date code. First quarter would be for the plug wires produced in the January to March window and third quarter would be the July to September window.

So in the case your car was produced in May of '65, you would want to purchase the first quarter of '65 plug wires. If you were searching out NOS plug wires, ideally, a second quarter of '65 would be better match. Production models manufactured between August and December would use the third quarter plug wires. Those manufactured between January and July would use the first quarter of the model year.

For whatever reason, if you should look a survivor cars with the original plug wires or boxes of NOS plug wires, you are very likely to see a combination of date codes. Nothing uncommon to see for example a set with a third and fourth quarter date codes.