1968 302 "J" Code Confusion

Discussion in 'Classic Mustang Specific Tech' started by 1stGenMustang, Sep 25, 2009.


  1. 1stGenMustang

    1stGenMustang New Member

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    The current mustang that I'm looking into is a "J" code 302-4V.

    According to my copy of the Mustang Recognition Guide "At the beginning of the 1968 production year, the 289 4-barrel and the 289 High Performance were dropped from the Mustang powerteam selection, and replaced with a brand new 302 4-barrel. The 289 2-barrel lasted until mid-year before being replaced by the 302 2-barrel. Two high performance engines were offered for the 1968 Mustang: a 302 High Performance and a 390 horsepower 427 - both were very limited production."

    As far as I can figure, the 289 4-barrel and the 289 High Performance are the 1967 "A" and "K" codes, respectively. And these codes did not appear in 1968 so the first sentence seems to make sense.

    The 289 2-barrel was the "C" code in both 1967 and 1968 so the second sentence also seems to make sense.

    But the third sentense is a bit confusing because the only 302 4-barrel code that I can determine is the "J" code. I cannot find a code for a High Performance 302 in 1968 -- like the famous 289 4-barrel "K" code.

    So:
    1) was there really a High Performance "K" code equivalent 302 4-barrel?
    2) or are they really talking about the 390 4-barrel "S" code and just typed 302 instead of 390?

    Also, does anyone know how many "J" codes were built in 1968 vs the other engines?

    Any help would be most appreciated...These Ford production quirks are maddening :)
  2. 2+2GT

    2+2GT Well-Known Member

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    1) No.

    2) No.

    The J code 302 4V was the replacement for the 289 4V. The "upgrades" were virtually identical to the "upgrades" of the 289 4V- Flat-top pistons, iron 4V intake, 4300 4V carb, specially curved distributor. The J code had special heads, which is actually pretty strange because they were no better than the 289 2V heads. One unfortunate side effect was the only engine available for the Shelby GT350 was the J code 302. Pretty lame compared to the 67 289 HP. In fact, early in the year the GT350 was delivered with the same exact engine as the Mustang, with the small 4300 carb and iron low-rise manifold. They even had the same exhaust manifolds as the 289 2V. Later, when the Cobra high-rise and Holley carb were smog-approved, owners were supposed to come back and have them installed. Some never did. Since the J code had the same cam and exhaust manifolds as the 289 2V, they really didn't help much.

    The 390 offered in the 68 Mustang* was the 390GT (not a "High Performance"), virtually unchanged from 66-69. *In 68 only, there was a seldom-ordered X-code 390 2V Premium Fuel engine, which had high compression but otherwise was strictly standard built 390 2V engine.
  3. 1stGenMustang

    1stGenMustang New Member

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    Thanks for the quick reply...Interesting stuff.
    The car I'm looking at is a convertible with factory 4-speed ("5") and 3.00 limited slip ("E"). And the Marti report doesn't mention the "GT Equipment Group" so I was figuring it was just a nicely optioned car.
    I love these forums -- always great help.
  4. 2+2GT

    2+2GT Well-Known Member

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    Interestingly, there were a lot of J code non-GT 68s. Funny, Ford dropped the J code. 68 was the only year for it.
  5. 1stGenMustang

    1stGenMustang New Member

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    Yeah, they kept the 302 2-barrel "F" code, I suppose as the "economy" V-8.
    That would seem to make the "J" code rather rare, being only available for 1 year...but not necessarily valuable?
  6. 2+2GT

    2+2GT Well-Known Member

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    I'd say the J code was worth 10%-20% more than an otherwise identical C code.
  7. 1stGenMustang

    1stGenMustang New Member

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    Great...thanks again.
    Too bad it's not a 390!!!
  8. D.Hearne

    D.Hearne Banned

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    The only different parts in a "J" code 302 are the heads and intake, both of which are the same parts used in the 66 289 4v motor, only with updated casting numbers. (C8ZE prefixes) The 427 option is often talked about, but none were ever built. It ended up being a Cougar only option for 68.
  9. john.m.barnes60

    john.m.barnes60 New Member

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    I know I'm a little late to the party on this post, was doing a google search and it popped up, but in 1968 Ford did offer a high performance version of the 302 however it was a very very limited production and they were coded as a G, these were race specific engines and were not available for public sale. These were the precursor to the Boss 302 in 1969 and featured a straight port cylinder head that was machined so the intake pushrod went straight through the center of the intake port. These were called the tunnel port 302's and were built for SCCA trans am racing. Only one was put in a street car as a prototype only and it is believed to have been crushed sometime in the mid 70's or even sooner. Car and driver go their hands on the car for a few days and pitted it against 68' Z/28 Camaro. Hot Rod magazine did an article on the failed 302 tunnel port in their may issue.

    http://www.hotrod.com/feature_stori..._iii_fated_1968_tunnel_port_302/photo_13.html
  10. horse sence

    horse sence Please don't call me Mom SN Certified Technician

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    i have never seen one in person .but if any one would have one it would be
    Al Vanderslice in farmersville . he was a drag racer in the 60s and has a stock pile that would put you in a coma .427 428 406 SOHC makes me dizzy just thinking about it :crazy:

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