MYSTERY K-FRAME

[CFD244]

Here is a continuation of a for sale thread that got some lively conversation started regarding a "Mystery" K Frame.

[SOLD] - K Frame

I found a stamping on the front center of the K frame found on my '71 (04 build) Demon. The stamp 45?M471, and there are no reinforcements for the lower control arm mounting holes. Any ideas?

 

[Scody21]

Here is a continuation of a for sale thread that got some lively conversation started regarding a "Mystery" K Frame.

[SOLD] - K Frame

I found a stamping on the front center of the K frame found on my '71 (04 build) Demon. The stamp 45?M471, and there are no reinforcements for the lower control arm mounting holes. Any ideas?

View attachment 1715729888

View attachment 1715729889

Thanks. I’m going to pull the one I posted out of storage, clean it up and look for numbers, take some measurements and see how a 340 block fits in it. Thinking that these K’s are a diamond in the rough...

 

[CFD244]

My numbers were stamped to the left of the center hole looking straight down at it. Check for the reinforced lower arm holes. Mine do not have the horseshoe shaped reinforcements.

 

[72bluNblu]

This was bolted to your '71 Demon?

The bottom view is a '73+ K frame. It has the provisions for the sway bar to pass through the bottom of the K frame. But it has the 67-72 biscuit style engine mounts on top.

Since it's unlikely the bottom section was removed and swapped out completely, I would guess that someone added the biscuit style engine mounts to a 73+ K frame.

 

[Scody21]

This was bolted to your '71 Demon?

The bottom view is a '73+ K frame. It has the provisions for the sway bar to pass through the bottom of the K frame. But it has the 67-72 biscuit style engine mounts on top.

Since it's unlikely the bottom section was removed and swapped out completely, I would guess that someone added the biscuit style engine mounts to a 73+ K frame.

The one I have does not look like it has been modified in any way. And what are the odds that there is more than 2 of these weird K frames out there. Was talking to a buddy and he was thinking that is a mid year f**kery or maybe a direct connection part. The mystery K frame continues....

 

[72bluNblu]

The one I have does not look like it has been modified in any way. And what are the odds that there is more than 2 of these weird K frames out there. Was talking to a buddy and he was thinking that is a mid year f**kery or maybe a direct connection part. The mystery K frame continues....

The only mystery is how it got that way. It's an A-body K frame with a '68-'72 upper section and a '73-76 lower section.

Got any close up pictures of the welds between the engine mounts and the K frame?

It may have been some kind of replacement K frame too, as it's been noted that there were other K frames like this in the late '72 cars. It wouldn't have made a difference back then, you could still attach the '67-72 sway bars to this K frame. Although now, you could also run a 73+ sway bar on this K frame.

 

[Kern Dog]

Ma Mopar did some weird stuff.

 

[Jim Lusk]

I have seen one of those. We pulled it out of a really rough '68 GTS convertible (not mine). I suspect the car has low miles due to still having the original engine with standard bore, but the body has taken its share of hits. My guess is that these were replacements in the mid-70s.

Yes, the GTS convertible will be restored and will be getting the correct 1968 K-member.

 

[autoxcuda]

I have a picture of one in a 72 slant 6 Dart.

not sure if this was a last year crossover deal or an over the counter replacement... or both.

Remember late 69 B-body K-members have the bottom halves of the 1970 pass through k-members. Even though the 69 sway bars bolt to the outside corners of the K just like A-bodies do. The pass thru k-member hole is not used one those 69’s.

So there is Mopar precedent to this type of deal.

but I also can see later over the parts saving the expense of stamping out two different lower halves when one lower half (73-76) would cover both applications.

 

[Mr. Sinister]

I have one that is for a V8 that has the 73’ and later open bottom. I pulled it from a 72’ Duster it doesn’t look modified I automatically just believed it was that way because it was a late production model. But now I need to look for a date stamp.
The pictured one at the start of this post looks like a slant 6 k member

 

[Mr. Sinister]

My “Mystery” K frame open bottom with 67’-72’ sandwich mount top. Last picture shows a slant 6 k frame with the flat almost over the control arm pivot bracket.