Bought these heads for my 340, found out after magging that the U head has some cracks that I really don't want to mess with. The X head is crack free. Both are 2.02/1.60 valves. Again, U head has some cracks between valves and between plug and valve. Make me an offer! Buyer will of course pay all shippings costs.
Here is the X head
I've never owned a small block but I always wondered what the difference was with U vs X.
Did the TA's and AAR's come with the X heads?
I've never heard of U heads. Were they very common? What engine and era?
Quote from: Cuda_mark on August 01, 2019, 05:47:39 AM
I've never owned a small block but I always wondered what the difference was with U vs X.
Did the TA's and AAR's come with the X heads?
J heads.
Took another look this morning. The U head has a 360 stamp on it, while the X head has a 340 stamp. From what I understand, both can be used on a 340.
1968-1969-(first half) 1970 model year 340s used "X" heads cast # 2531894 with 2.02"/1.60" valves
(second half) 1970-1972 model year 340s used "J", "O", "U", "Z" heads cast # 3418915 with 2.02"/1.60" valves (at some point & on 360s with 1.88"/1.60" valves)
340+6 T/A heads are "J", "O", "U", "Z" heads cast # 3418915 with offset intake pushrod holes and 2.02"/1.60" valves
1973 model year 340s used heads cast # 3671587 with 1.88"/1.60" valves (also used on 360s)
6bblgt, can you elaborate a little more?
What would a November '69 built Challenger 340 have?
Located in California near Modesto. I'll get a photo this afternoon.
Yep, I think you're right. My J heads were made July 8th, 1970.
No one has been able to produce a photo of a 69' built J head (915) that I've seen.
OP, can you post a picture of the date codes?
http://www.cuda-challenger.com/cc/index.php?topic=119591.0
Here are pictures of the stamping on the head.
Quote from: Teslasbrain on August 01, 2019, 03:29:34 PM
OP, can you post a picture of the date codes?
http://www.cuda-challenger.com/cc/index.php?topic=119591.0
I would love to see evidence that ANY 1970 Challenger got a "J" head!
How about a 70 Cuda? Got one in my shop right now with J heads... Prior to me it was un-molested... I on the other hand have molested it.... Just call me Chester...
Randy, remove the valve covers and take a picture of the date codes please!
It's not "impossible" that J heads could be produced in 1969, it's just very very rare, and I think 6bblgt is just trying to document when the first may have been casted. It certainly would NOT be before November of '69. Maybe "J"'s started November-December of 69. But again, there's been zero posted proof so far.
My engine was casted Sept 12 of 1969. The J heads are absolutely "wrong". Would love to begin documenting when "J" heads replaced "X" heads.
For science!
Quote from: kawahonda on August 01, 2019, 07:44:51 PM
Randy, remove the valve covers and take a picture of the date codes please!
:haha: :haha: :haha: I want the car finished & gone... You think I'm gonna take it back apart... Not Happening...
Quote from: 1 Wild R/T on August 01, 2019, 09:13:36 PM
Quote from: kawahonda on August 01, 2019, 07:44:51 PM
Randy, remove the valve covers and take a picture of the date codes please!
:haha: :haha: :haha: I want the car finished & gone... You think I'm gonna take it back apart... Not Happening...
how about what's the cars VIN and/or SPD, surely it is during the 1970 calendar year
& all T/A & AAR cars are 1970 340s with "J", "U", "O" or "Z" heads :thinking:
There's no performance difference between X and early J heads. It's only the J heads that are produced "sometime" during 1969 model year, which hasn't been visually documented on this forum yet.
If heads are casted after VIN date, they are not the correct heads. Mine is a example.
Two things that are left not well documented, and this is why 6bblgt is the man for this:
1) When X heads shift to J heads for 70-71 340 builds. We have a rough clue that is "could" be last couple months of '69, but no hard evidence. Almost everything you see online of 915 castings has a casting date in 1970. Every single time. I'm starting to think 915 were not casted in '69, but I haven't closed that option up yet...
2) my soapbox time......the LD340 changes throughout production cycle.
a) Some LD340 have Chrysler part # and divorced choke mount
b) some LD340 have Chrysler part # and no divorced choke mount.
c) some LD340 have no Chrysler part # but have a divorced choke mount.
d) Some LD340 have no Chrysler part # but do not have a divorced choke mount.
No one at all knows any history on this. I think this is just as important as any other Mopar history....
1) is easier to solve, it would seem! I could remove and reinstall LA valve covers in 10 minutes flat while drinking. Not a serious en-devour at all.
340s are confusing, but that's why they are so fun. My 340 is "late" enough to get the 14" Ralleye rims, but early enough to get zero metal hood badges. You know how many people think that's weird, even mopar people? 99.9% think the sticker is not stock.
Others have got metal hood badges and 14" rims (must be after Nov ' 69). Seems much more common to see this.
I wonder if 1970 340s that got the 15" Ralleyes ALWAYS got the decal hood badges. At this point, that statement must be a fact....otherwise there's no logic. These must be an ultra rare-breed.
:fingerscrossed:
Quote from: 6bblgt on August 01, 2019, 10:45:35 PM
Quote from: 1 Wild R/T on August 01, 2019, 09:13:36 PM
Quote from: kawahonda on August 01, 2019, 07:44:51 PM
Randy, remove the valve covers and take a picture of the date codes please!
:haha: :haha: :haha: I want the car finished & gone... You think I'm gonna take it back apart... Not Happening...
how about what's the cars VIN and/or SPD, surely it is during the 1970 calendar year
& all T/A & AAR cars are 1970 340s with "J", "U", "O" or "Z" heads :thinking:
Yes, it is... It's a fairly late car... I'll post the info later today.... I was responding to this....
Quote from: kawahonda on August 01, 2019, 07:15:41 PM
Quote from: Teslasbrain on August 01, 2019, 03:29:34 PM
OP, can you post a picture of the date codes?
http://www.cuda-challenger.com/cc/index.php?topic=119591.0
I would love to see evidence that ANY 1970 Challenger got a "J" head!
X Head sold. Still have the U head available, open to all offers!
Quote from: kawahonda on August 01, 2019, 11:18:21 PM
There's no performance difference between X and early J heads. It's only the J heads that are produced "sometime" during 1969 model year, which hasn't been visually documented on this forum yet.
If heads are casted after VIN date, they are not the correct heads. Mine is a example.
Two things that are left not well documented, and this is why 6bblgt is the man for this:
1) When X heads shift to J heads for 70-71 340 builds. We have a rough clue that is "could" be last couple months of '69, but no hard evidence. Almost everything you see online of 915 castings has a casting date in 1970. Every single time. I'm starting to think 915 were not casted in '69, but I haven't closed that option up yet...
2) my soapbox time......the LD340 changes throughout production cycle.
a) Some LD340 have Chrysler part # and divorced choke mount
b) some LD340 have Chrysler part # and no divorced choke mount.
c) some LD340 have no Chrysler part # but have a divorced choke mount.
d) Some LD340 have no Chrysler part # but do not have a divorced choke mount.
No one at all knows any history on this. I think this is just as important as any other Mopar history....
1) is easier to solve, it would seem! I could remove and reinstall LA valve covers in 10 minutes flat while drinking. Not a serious en-devour at all.
340s are confusing, but that's why they are so fun. My 340 is "late" enough to get the 14" Ralleye rims, but early enough to get zero metal hood badges. You know how many people think that's weird, even mopar people? 99.9% think the sticker is not stock.
Others have got metal hood badges and 14" rims (must be after Nov ' 69). Seems much more common to see this.
I wonder if 1970 340s that got the 15" Ralleyes ALWAYS got the decal hood badges. At this point, that statement must be a fact....otherwise there's no logic. These must be an ultra rare-breed.
:fingerscrossed:
Interesting point made;
My A66 Challenger vert with a SBD of October 7th, 1969 came with the 15" rallye wheels and the 340 decals on the hood.