1977 302w production date problem

Hello all! I have recently acquired a '77 Ghia w/ 302w. Upon changing out the cap/rotor/plugs/wires I found that the 302w had two production phases that year: pre June 28th and June 28th on. Dealerships and part stores all offer different wire lengths for based on the split, neither of which match what is on the car now! I tried the earlier set, but it ran squirrelly and so I'm still using the old wires, which are motorcraft with "1977" printed on them. I can't see the block stamp as the exhaust covers it well, though even if I could, the two offered sizes don't match what seems to work on there now. Any suggestions on proper matchup? I already know I can cut a set to fit whats on there now, but I have no idea if those are even the right set.
 
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Hello and welcome to Stangnet! :)

I'll admit, I never really knew of a difference in OEM spark plug wires for our vintage engines unless a boot had changed or something. So I checked O'Reilly's site to see what they offered. They list 1 brand that specifies a date as you said, all of the others do not. Incidentally, these are also the least expensive. Given that, it very well could be that you've gotten a bad product. I run Ford Motorsport wires on my car and have 0 issues, so I would have no problems recommending them for anyone else. The downside is if you're looking to save some money they're more expensive.

As far as wire lengths go, the only thing I can think of is that one set would be designated for a 302, the other set designated for a 351 OR if it's labeled as universal BECAUSE of the 351.
 
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Hello and welcome to Stangnet! :)

I'll admit, I never really knew of a difference in OEM spark plug wires for our vintage engines unless a boot had changed or something. So I checked O'Reilly's site to see what they offered. They list 1 brand that specifies a date as you said, all of the others do not. Incidentally, these are also the least expensive. Given that, it very well could be that you've gotten a bad product. I run Ford Motorsport wires on my car and have 0 issues, so I would have no problems recommending them for anyone else. The downside is if you're looking to save some money they're more expensive.

As far as wire lengths go, the only thing I can think of is that one set would be designated for a 302, the other set designated for a 351 OR if it's labeled as universal BECAUSE of the 351.
I can only find motorcraft at dealerships around me, but I don't mind spending a little dough to get her running right. I dropped $10k on a mustang II (no rot), and can't let my wife know it's got issues, . I have a holly carb coming soon and I think most of my shimmy is from carb issues anyway. It just seems some of the wires are weirdly tight, but I triple checked the firing order. The Chilton's manuals shows a front right distribution location, while mine is front center. I'll post that pick anyway, maybe someone knows something. Yankee Ford of South Portland ME gave me two build date options like O'Reilly, AutoZone and Advanced Auto did, so it seems industry wide, but cjpony doesn't specify, nor do manuals. The car was completed 11/76, which makes me assume it's a pre June 77 engine, but no guarantee it's original, but likely.
 
I can only find motorcraft at dealerships around me, but I don't mind spending a little dough to get her running right. I dropped $10k on a mustang II (no rot), and can't let my wife know it's got issues, . I have a holly carb coming soon and I think most of my shimmy is from carb issues anyway. It just seems some of the wires are weirdly tight, but I triple checked the firing order. The Chilton's manuals shows a front right distribution location, while mine is front center. I'll post that pick anyway, maybe someone knows something. Yankee Ford of South Portland ME gave me two build date options like O'Reilly, AutoZone and Advanced Auto did, so it seems industry wide, but cjpony doesn't specify, nor do manuals. The car was completed 11/76, which makes me assume it's a pre June 77 engine, but no guarantee it's original, but likely.
There's also no guarantee that the distributor wasn't changed in the 45 year since it was built.

The difference between the plug wires is that the earlier wires are the old-fashioned type where you push the plug wire terminal into the cap, where as the later style is more modern in that you push them onto the cap.
 
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I believe Matt is correct. That is about when they changed from the skinny male to the short/fat female dizzy caps. Iirc this was to prevent arcing on the higher output ignition systems.
 
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Hello all! I have recently acquired a '77 Ghia w/ 302w.
Aloha and welcome aboard.
Happy for new blood around here. We are pleased to ask for a picture your Ghia.

I'm still using the old wires, which are motorcraft with "1977" printed on them.
We want to see these too, just for fun. I bet no one at Ford thought them wires would go 45 yrs.
 

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Right about when he is talking is when they changed the way the wires were held in place
The before ones would have the square wire retainer on the tab atop the valve cover
The later ones would have the valve cover bolts with the post on the bottom 3 for the new style wire retainers
Each wire will be different between the 2 styles
 
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Right about when he is talking is when they changed the way the wires were held in place
The before ones would have the square wire retainer on the tab atop the valve cover
The later ones would have the valve cover bolts with the post on the bottom 3 for the new style wire retainers
Each wire will be different between the 2 styles
This sounds like good intel, I'll look into that, thanks
 
Love the color.

I have those same wheels on the coupe i am slowly getting back together. Do you have spacers on them?
Haven't taken them off yet to see, but after I swap the 2150 (297cfm) for a Holley 500cfm, if that steadies out my fuel delivery quirks, I plan to split the exhaust with new polished manifolds and straight pipes (its got a cat and one pipe, I must be bleeding HP). Then, I intend to finish her off with a fresh set of chrome 4-point rims to match oem. Someone added those foxbody rims before me. I'll post those rims on Maine Craigslist after (or keep them as a excuse to slowly build a fox body from the rims up!)