Well I've been hearing from alot of different people about the letters on the heads, some meaning they are high performance and what not. I am interested because I have a 318 from the factory I just pulled out of my car and it has X heads(with turquoise colored springs) and a couple more sets of heads. So what letters are high performance?
special heads?
- Thread starter 74dart
- Start date
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$50 for the pair.....Just kidding, the x heads are the "desirable" 340 heads.
fishy68
Tyr Fryr's Inc.
They never put X heads on a 318 so either your 318 isn't a 318 or someone put the X heads on it. Probably the latter.
X heads are 68-70 340 heads.
As far as what heads are the high perf. heads. There were the X heads and 71 J heads. 72 and up J heads have smaller valves so their not really considered high performance although they are still very good heads.
If you only plan on selling the X heads sell them as-is. I say that because by the time you have them rebuilt you could easily have $700 wrapped up in them and they don't bring much more than that. Stock/un-rebuilt will bring $200-400 depending on the condition.
X heads are 68-70 340 heads.
As far as what heads are the high perf. heads. There were the X heads and 71 J heads. 72 and up J heads have smaller valves so their not really considered high performance although they are still very good heads.
If you only plan on selling the X heads sell them as-is. I say that because by the time you have them rebuilt you could easily have $700 wrapped up in them and they don't bring much more than that. Stock/un-rebuilt will bring $200-400 depending on the condition.
damnimcooltom
Too Cool For School
A casting number (7 digit) would be more helpful than anything to help ID the heads.
Sometimes there's no number between the plugs. The "X" or "J" or whatever letter there is, is located on the under side of the head, close to the casting number.
fishy68
Tyr Fryr's Inc.
I agree as they don't always have a letter on them.
damnimcooltom
Too Cool For School
Not the "X" we're looking for. The 7 digit casting number will tell us more.
The X head numbers are
2843675
and I have a rebuilt set of L heads I was told were high performance with the numbers being
4027593
They have some extra ports for water it seems like but the spring size, valve size and other ports all look the same as the x heads
2843675
and I have a rebuilt set of L heads I was told were high performance with the numbers being
4027593
They have some extra ports for water it seems like but the spring size, valve size and other ports all look the same as the x heads
gilgalad1138
Well-Known Member
Don't think those are X heads.. just did a quick search and they look like they're stock 273-318 closed chamber heads. Could be wrong though.
fishy68
Tyr Fryr's Inc.
2843675 heads are not 340 X heads. I see the X in your picture but that's not where it's located on 340 X heads. The X on 340 X heads is located between the spark plugs as mentioned above and sometimes it's not even there but is on the underside of the intake runner.
There is only 1 casting # for 340 X heads and it is 2531894
2843675 heads are 318 heads used from 68-74
4027593 heads are 318 heads used from 77-83
Neither are high performance heads. Just standard small valve 318 heads.
fishy68
Tyr Fryr's Inc.
Yep.
fishy68
Tyr Fryr's Inc.
Your welcome
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