68 kframe vs. 73 & up

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rudmover

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I was hopeing to find a later K frame within a reasoable distance from home(oregon coast) my thinking was the spool type mounts and swaybar setup was better on the later K frames, I have also read that the Idler arm is somehow better. Is this all true I could really use some input on this subject from you guys in the know. I plan on tubular upper arms stiffening plates for the lowers to go along with the poly(graphite inpregnated)bushings and 1" torsion bars I already have, I have everything stripped already but don't really want to waste time with this 68 (Barracuda) K member unless It has some advantages over the later model. I plan for this car to handle so it will be getting torque boxes as well as frame connectors. Maybe I'm being rediculous but I want the best setup on a tight budget that I can get so a tubular k member is out of the question for now. thanks for any input I get
 
Better for what? If your just putting in a SB I dont really see a difference. But if your are upgrading brakes you will need parts off a 73+ K frame if you doing a stock change and not aftermarket. What are your issues with using the 68 k frame you have now?
 
As far as I know the only real differences is the later model has cutouts in the sides so the sway bar threads through the K. I wont say you can cut the 68 K since I haven't tried it. And the spool type motor supports.
The 67 idler arm is the different one. 68 up are about the same.
 
I like the spool k-frames, for several reasons. I like them so much I even cut one down to fit in my '63 Valiant.

1. The motor mounts wont break and cause your motor to lift and cut your upper radiator hose. But, you can get around this with some aftermarket biscuit motor mounts with a screw that makes it impossible to tear the motor loose.

2. The swaybar is much tighter to the chassis and doesn't limit front tire size like the earlier k-frames where the sway bar mounts out in front of the k-frame and has longer arms than the later one. The later swaybar is easier to mount, and with it's shorter arms it is much more effective for the diameter (although this might be a wash as the later bar mounts to the lower control arms farther from the lower ball joint, which reduced the effectiveness). At the same time, you can now buy aftermarket earlier front mount swaybars with a bend that give tire clearance.

3. The 73 and up k-frame does have a different idler arm mount, that is much more effective. The idler has a through bolt instead of mounting on a stud to a plate. This makes the mount much more effective, enough so that I think it is the only way to go. There is no work around for this on the earlier k-frames, short of cutting the idler arm mount off a later k-frame and welding it to your earlier one. No thanks.

If you want the car to handle, you are going to have to deal with deflection in your steering if you run the stud mounted idler.
 
Thanks guys this is what I needed to know. I already have the disc brake setup from a later a body upper arms spndles and such. so I guess I'll start looking for the later K frame. I also want to find some caliper mounting brackets for 11 3/4 rotors so It will be a bit before assembly anyway.
 
I think the late model has a wider track then the 72 and down....... 1/2 if I remember correctly

That I did'nt know. Will this cause geometry issues or can it be dealt with to fit a 68 barracuda?
 
So anyone know what's involved in making a later one fit in a 68 barracuda? I am fortunate enough to have some welding skills but also a son who is a metal fabricator.
 
All 67-76 a body k frames interchange. 67 was 1 year only idler & pitman arms. 68-72 was the same k frame & 73-6 is the same
 
sweet, thats good news thanks all you guys, hopefully soon I'll start a build thread and start organizing all these pics I've been takin.
 
So with the 67 pitman arm thing, is it just the mount that is different or is the whole arm different? I have 67 Dart now with what I assume to be the stock K member (modified with welded on spool type mounts), but I have a 73 K member ready to swap in at some point. Will I need to be getting new arms or will the existing arms just mount differently in the new frame?
 
Pitman arms and idler arms are a booger to keep sorted. The 67 idler arm is what it is, different from all others. 68 to 72 are the same in how the mount to the K and to the drag link . 73 to 76 pitman and idler still the same at the K but different in how they attach to the center link. So yeah the center link changed in 73 up. Having fun yet ? If you stick with manual steering you'll probably get it together but, if you get the later K with a power steering gear on it you may find yourself searching for a pitman arm that was never made. You wouldn't be the first. Hope this helps. Good luck
 
Wow, do I feel foolish. I was convinced that the 73 and up idler mounted to the k-frame differently than the 72 and down ones. I have since proven myself wrong (see this link), by information I myself posted 3 years ago. My only defense is that I turned 42 today, must be old age.

Not certain, but I think the 68-72 idler mounts the centerlink below the idler, while the 73+ idler mounts it above. So, Map63Vette, you should be able to use your existing pitman arm and centerlink if you use a 68-72 idler arm.
 
Hmm, okay, I guess I'll have to have a good look at everything. It's a power setup right now, and while I don't really care a whole lot whether it stays that way, I'm short enough on money that it's probably going to have to since I don't want to mess around with adapters and new boxes to put manual in it. Crossing my fingers for the best, lol.
 
I think the '73 and up K frame design is better than the '72 and earlier design. Having said that, I'm in the process of removing a '73 K frame from a 1968 Valiant and installing a re-worked '72 K-frame. Only reason we're doing that is to gain more room for the oil pan. The steering linkage will stay '73 style because it is better. The steering knuckles are from a FMJ, anti-sway bar will be custom to work with the '73 lower control arms.

Some of this stuff gets confusing! Have to have a scorecard to keep it straight.
 
I need to find whoever put my car together to start with, lol. It's pretty much the junkyard special from what I've been able to sort out so far. 67 VIN with 69 sheet metal and grille, F body 8.25 rear end complete with entire rear spring setup (rubber spring isolater axle mounts to boot), some kind of BBP front discs (caliper casting number matches a 73 Cuda, but I'm guessing it's probably also off the same F body, some mid 70's 318 with some giant radiator that I assuem came with the engine (maybe an A/C car that they didn't take the A/C with), and a 73 4 speed. "Custom" welded engine mounts (by that I mean they cut the original biscuit style off the K frame and transplated the spool mounts that came with the engine along with some nice angle iron and square tube to get them where they needed to be). It's fun going to the part store anymore, I've told them about 5 different cars so far when buying parts.
 
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