340 K Member ??

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DFX, torque boxes are sheetmetal boxes that the factory used on Hemi and convertible models (in this case, a select few A-bodies) to strengthen the uni-body design and improve handling (factory subframe connectors). These boxes are located behind the front wheels and in front of the rear wheels and link the rocker panels to the frame. Torque boxes were sometimes installed on 440 cars and were a "hit and miss" add-on, depending on what the factory had in stock on a particular day. Even if your vehicle did not have factory boxes, they can easily be added to your A, B or E body Mopar. There are a number of companies that re-pop them - I got a great set from Rick Kruziger out of WI. I searched here on FABO for a string related to torque boxes but not much. A far as I know, a good number of '70 Swinger 340 cars got them but don't know if any 340 Dusters or Demons got them as well. This also made me raise the question of the washers, maybe they indicated that boxes be added to the car... I think I might start a string asking the A-body torque box question - which cars got them etc.

Torque box update #2: The 69 Polara Convertible (HP 383/727/2.76 489 case differential) has a box-type sheet metal arrangement just forward of the leaf spring hangars. A large hole is cut out in the bottom sheet metal to allow for access to the hangar nuts. I have a 69 Polara Hardtop Coupe (factory numbers matching 318/A904/2.76 741 case differential) as a donor car and the box is not there. The hangar nuts are plainly visible. The front area ahead of the rockers is identical for both of those cars.

My duster has a sheet metal arrangement similar to the convertible at the leaf spring hangar location.

Cliff, I think you should ask for a check for the presence of torque boxes on all 340 cars with the washer on the K member. It would also help if we could poll for the boxes on any known factory 318 A-bodies for the 1970 -1974 years.

Art

Just went to Mopar Muscle Magazine website and found pictures of an add-on torque box. Now that I know what they look like I can say that my convertible and my 340 Duster have them.
 
Sounds like a plan, let's see if we can make a spread sheet type document (oooh, almost sounds like working in an office) and see if there's a common denominator. Let's break it out something like this:

Year and model, transmission type, brakes - disc or drum, sway bar, torque boxes - front, rear or all 4 and finally if it has the welded on washer.

'70 340 Swinger, 4 spd, disc, sway bar, front torque boxes, with washer
'72 340 Swinger, auto, drums, sway bar, 4 torque boxes, with washer
 
could the washer be a vendor identification thing? Who built the K members?
Maybe ill ask another way. Where were the K members manufactured? Did each Chrysler plant build there own K members or were they outsourced like starters, brake components,etc. The washer could be a plant I.D.
 
This is from a 69 340 4 spd drum brake swinger. the car is long gone, still have the trans and rear, motor was not the original 340. dont remember the build date. But mine dosent have a washer more like a tag just got it back from the blaster. Just more to add to the mix.

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This is from a 69 340 4 spd drum brake swinger. the car is long gone, still have the trans and rear, motor was not the original 340. dont remember the build date. But mine dosent have a washer more like a tag just got it back from the blaster. Just more to add to the mix.

That one is different for sure...That's a full disc welded on.

Thanks for sharing.
 
Hey DFX – replying late to this one but is that for sure that only 4 speed cars got torque boxes? My 72 automatic has on all 4 corners and I said the 70 340 4 speed car has on front but might be on all 4 as well. Do we know if they split up with only 2 on the front or 2 on the back? I have seen a couple with only 2.
How about 340 Dusters and Demons (didn't check or ask) - I've only seen them on 340 equipped Swingers.

ALL 70-71 Duster and Demon 340 4-speed cars that I've seen has the torque box plates front AND rear. I have never seen a automatic 340 A-body of any sort with those plates whether in front nor in back. I've heard all convertible A-body cars had them no matter what engine they were produced with but will be on the look out to verify this. Convertibles do not last in Hawaii (very rare) as they tend to return to its natural state...iron ore...rust...
 
Bumping this thread after reading it thru today and after a quick peek at my car.

'72 340 Demon, 4-speed, disc, sway bar, four torque boxes with washer.
 
Hmmm, so, who's going to attempt to put all the data together, calculate, add up and come to an educated conclusion as to why the factories welded a washer (or as we just saw, a disc) to indicate that a 340 is going to drop into this car. Or, is someone going to come across this and say they know exactly why, because they were on the floor at that time...
 
I worked in an assembly plant for 31 years and maybe 5 or 6 of those were in the chassis department, frame line to be exact. Im thinking that since this seems to have begun all at once (in 1970) that the vendor for the K-members made a change to the dimensions during a model change over and the assembly plant didnt make a change to their tooling/fixtures OR vice versa. The washer could have been put there for a quick fix as a spacer/shim to correct the tooling/fixtures at the other end (assembly line). Being as this seems to be 340 engines only it could be that there was a certain operation to be done to that paticular model. Fixtures would be to hold something in place while a part was welded on, a hole drilled, an A arm held in place, etc etc and or maybe the hole in the washer was used for a "locator". This is my utmost professional educated guess LOL TYVM.

Like him?
 
i think its supposed to strenthen the lower control arm mount....i noticed it a long time ago on 70 and up cars mostly sway bar cars.my 70 318 has one and its factory but it also hs a z-bar mount welded to the frame with under coating.weird wild stuff!
 
The V-8 K-frame that I got with my 4 speed conversion parts has the washer welded to the front. I think the guy said he pulled it from a red (floor hump was red) '72 Duster 3 speed (original trans was in the trailer with all the other parts). I guess the car was a 340 Duster. He pulled the car out of a junk yard, took the parts off it and sent it back :( Never saw the car.
 

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When this washer is in place the car gets HD. torsion bars. 68 and 69 would have heaviest 894 and 895 bars. WITHOUT THE WASHER 70 would have the heaviest 892 and 893. I have seen two on 68's one was a 68 Dart GTS 340 4spd. The other was on a 68 383 4spd barracuda.
 
This is very interesting. I had a 72 swinger 318 2 barrel auto trans. kh disks no sway bar it did have ps and power brakes and ac. So I'm thinking that it might be a torsion bar thing. It did have the washer. I remember it well because I asked my dad why it was there. He simply said because someone felt like welding one there.
 
I'm going to revive this old post with a related question.When did they switch,or what determined a car with a "closed" bottom k frame to an "open" bottom frame? I have a 20K survivor 72 Duster that has the washer and an open bottom k frame.But most other I have seen have a closed bottom.Any reason for this?
 
I'm going to revive this old post with a related question.When did they switch,or what determined a car with a "closed" bottom k frame to an "open" bottom frame? I have a 20K survivor 72 Duster that has the washer and an open bottom k frame.But most other I have seen have a closed bottom.Any reason for this?
Does your car have the spool type or the wafer type engine mounts.
 
I'm going to revive this old post with a related question.When did they switch,or what determined a car with a "closed" bottom k frame to an "open" bottom frame? I have a 20K survivor 72 Duster that has the washer and an open bottom k frame.But most other I have seen have a closed bottom.Any reason for this?

73 they went to spool mount. more open bottom of the k-frame.
 
I am going to have to check.I just poked my head under there earlier and noticed the 340 washer and the open bottom.
 
My brown 72 I just sold had the 67 to 72 mounts with the open bottom k frame...it was a late 72 maybe even the very last one.
It was a 318 with ac and has 892/893 torsion bars too and called for them on the build sheet.
 
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Well I can state that I have a 72 340 4 speed car with the biscuit style mounts and the closed bottom with the washer welded to it. I'm not going to say never, but I have never seen a 72 or earlier A-body with a open bottom.
 
10 years later but I just noticed this. All the washers I've seen or what was posted here were washers with holes. Member Swingr340 posted his K-frame from a 69 340 4-speed that has a round disc without the hole like washers has. There was an earlier post that someone said his has a "tag" instead of a washer.
K-frame Washer 8.jpg
 
10 years later but I just noticed this. All the washers I've seen or what was posted here were washers with holes. Member Swingr340 posted his K-frame from a 69 340 4-speed that has a round disc without the hole like washers has. There was an earlier post that someone said his has a "tag" instead of a washer.View attachment 1715501420
Musta run outa holes. :poke:
 
My numbers matching 4-10-1970 Swinger 340 has the washer on the front of the K frame. I'll try to get photos tomorrow, time permitting. Things are a bit scary in western Washington right now. Prayers for all. Semper Fidelis.
 
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