73+ K-frame build (pics)

[go-fish]

This 73+ k-frame is going in a 1969 Valiant.

Firm Feel gusset kit.
Seam welded.
Firm Feel roller idler arm kit.
LCA plates.
Bergman Autocraft Delrin bushings and pins.
QA1 strut rods.
Hellwig 5905 1-1/4" sway bar.

Not being used are my Hotchkis fast ratio pitman/idler arms ( [FOR SALE] - Fast Ratio Pitman/Idler Arm ) as they won't clear the TTi's without some surgery to one of the primaries. I am using K7075 Moog pitman. Also, I have some Proforged LBJ's, SPC (old style) UCA's, OEM spindles, Viper brake kit, & little button bump stops to put on, so stay tuned.

The QA1 torsion bar adjusters came with 4 thick washers but I couldn't figure out where they go. Anyone know?

The roller bearing idler arm takes a lot of work to do but not hard. The sway bar was a pain to install. The bars that the bushings mount to took a bit of grinding to fit on the k-frame properly and I am displeased with the bolts. It's only 1-1/4" and I couldn't find one that was 1-1/2". The 1.24" torsion bars and Hotchkis Fox shocks will make up for the .25" I think.

Coming at a later date will be a PST or Firm Feel 16:1 box to replace the core box I have on there now.

Oh, btw, I was really excited that when I went on Rock Auto and found 340 engine mounts. Beware, they're just 318 mounts. I just used some thick washers on the different mount.

 

[Blind Squirrel]

 

[Oldmanmopar]

Take a pry bar and see if you can pry the lower control arms rearward on the pin at the bushing with the swivel strut rods you have. You may have to remove the stabilizer end link on 73 up 340 suspension. You don't have to on the 72 and earlier

I would say the washers you received with the torsion bars may go behind the bar in front of the clip to prevent the bars from siding back and hold the arms on.

Just my advise do what ever you want. I have just seen a car with a destroyed fender and valance due to this.

 

[Rat Bastid]

What happened to the 69 biscuit mount K frame.

 

[go-fish]

What happened to the 69 biscuit mount K frame.

Bought the car after it had already been converted to BBP using the late k-frame.

 

[go-fish]

I would say the washers you received with the torsion bars may go behind the bar in front of the clip to prevent the bars from siding back and hold the arms on.

Well, I’m a dummy. After some head scratching I remembered they’re AR Engineering camber spacers. Duh. I just had them in the same little box with the t-bar adjusters.

Mancini Racing Camber Spacer Kit

 

[72bluNblu]

This 73+ k-frame is going in a 1969 Valiant.

Firm Feel gusset kit.
Seam welded.
Firm Feel roller idler arm kit.
LCA plates.
Bergman Autocraft Delrin bushings and pins.
QA1 strut rods.
Hellwig 5905 1-1/4" sway bar.

Not being used are my Hotchkis fast ratio pitman/idler arms ( [FOR SALE] - Fast Ratio Pitman/Idler Arm ) as they won't clear the TTi's without some surgery to one of the primaries. I am using K7075 Moog pitman. Also, I have some Proforged LBJ's, SPC (old style) UCA's, OEM spindles, Viper brake kit, & little button bump stops to put on, so stay tuned.

The QA1 torsion bar adjusters came with 4 thick washers but I couldn't figure out where they go. Anyone know?

The roller bearing idler arm takes a lot of work to do but not hard. The sway bar was a pain to install. The bars that the bushings mount to took a bit of grinding to fit on the k-frame properly and I am displeased with the bolts. It's only 1-1/4" and I couldn't find one that was 1-1/2". The 1.24" torsion bars and Hotchkis Fox shocks will make up for the .25" I think.

Coming at a later date will be a PST or Firm Feel 16:1 box to replace the core box I have on there now.

Oh, btw, I was really excited that when I went on Rock Auto and found 340 engine mounts. Beware, they're just 318 mounts. I just used some thick washers on the different mount.


View attachment 1715857437 View attachment 1715857438 View attachment 1715857440 View attachment 1715857441 View attachment 1715857442 View attachment 1715857443 View attachment 1715857444 View attachment 1715857445 View attachment 1715857446 View attachment 1715857447

Huh. I run the Hellwig 55905 on my Duster, I don't recall the mounts taking much work to fit the K. I seem to remember I had to do a little fitting but that's pretty much every aftermarket part made. The 55905 is a 1-1/8" diameter bar, the 73+ Hotchkiss is 1-1/4" but since neither one tells you the actual rate or gives the tube thickness it doesn't necessarily mean they're substantially different. The 67-72 Hotchkiss front bar is 1.5", but, the lever arms are different lengths compared to the 73+ bars too so the rate may be the same/similar.

Either way I don't think you'll need more sway bar with 1.24" torsion bars. If anything, depending on your tires and usage you may need less wheel rate than what that will give you.

Take a pry bar and see if you can pry the lower control arms rearward on the pin at the bushing with the swivel strut rods you have. You may have to remove the stabilizer end link on 73 up 340 suspension. You don't have to on the 72 and earlier

And if you do this and your LCA's move more than they would with the factory strut rods and bushings, you need to adjust the strut rod length. Because when properly adjusted the LCA's will move around less with the Delrin LCA bushings and adjustable strut rods than they will with factory rubber bushings. That's literally why there are Delrin LCA bushings and adjustable strut rods on the market, to get rid of the slop created by the factory rubber bushings.

I would say the washers you received with the torsion bars may go behind the bar in front of the clip to prevent the bars from siding back and hold the arms on.

ROFLMAO. No, that's not what they're for

Just my advise do what ever you want. I have just seen a car with a destroyed fender and valance due to improperly installed strut rods and/or LCA bushings.

Fixed it for you!

Remember, there are more than a few guys that run their Delrin LCA bushing and adjustable strut rod equipped cars on road and autoX courses at high speeds without any hint of this being a problem. Peter Bergman @BergmanAutoCraft had the Delrin bushings made specifically based on his experiences with driving his car on road courses. If the LCA moved and the tire ate the fender and valance it was either improper installation or a part failure (which may have still been improper installation). Because with proper installation of those parts the LCA will not move around like that.

Well, I’m a dummy. After some head scratching I remembered they’re AR Engineering camber spacers. Duh. I just had them in the same little box with the t-bar adjusters.

Mancini Racing Camber Spacer Kit

You shouldn't need those with the SPC UCA's unless you're planning some really crazy camber numbers. I have a set somewhere too, back from before I bought the SPC's. Never used them.

 

[go-fish]

Huh. I run the Hellwig 55905 on my Duster, I don't recall the mounts taking much work to fit the K.

Just had to grind had to grind the plates and get new hardware. The plates were a little long. Also, the stamping of the k-member leaves a radius so I made a radius when I was grinding for fitment. The bolts were like less than grade 5. The end link bolts from Hellwig are 7” long leaving more thread than I want hanging under the lower control arm.

 

[go-fish]

And if you do this and your LCA's move more than they would with the factory strut rods and bushings, you need to adjust the strut rod length. Because when properly adjusted the LCA's will move around less with the Delrin LCA bushings and adjustable strut rods than they will with factory rubber bushings.

Oh they’re tight. I actually think I need to back the strut rods off a hair. Which brings up a question. Do I need to have anything loose or backed off when going from an unloaded suspension to loaded suspension upon install? The torsion bar adjusters need to be backed off right?

 

[go-fish]

You shouldn't need those with the SPC UCA's unless you're planning some really crazy camber numbers. I have a set somewhere too, back from before I bought the SPC's. Never used them.

Yep. They were an old purchase for me too. I had totally forgot about them and guess I had stuffed them in the box with the adjusters. Took me awhile to remember what they’re even for.

 

[autoxcuda]

Take a pry bar and see if you can pry the lower control arms rearward on the pin at the bushing with the swivel strut rods you have. You may have to remove the stabilizer end link on 73 up 340 suspension. You don't have to on the 72 and earlier

I would say the washers you received with the torsion bars may go behind the bar in front of the clip to prevent the bars from siding back and hold the arms on.

Just my advise do what ever you want. I have just seen a car with a destroyed fender and valance due to this.

Did that happen with a drag car. I could see that with light T-bars and a car lifting the front end way up. Especially repetitively slower working it’s way out.

Or some other situation where the suspension was very unloaded?

 

[Oldmanmopar]

Did that happen with a drag car. I could see that with light T-bars and a car lifting the front end way up. Especially repetitively slower working it’s way out.

Or some other situation where the suspension was very unloaded?

Hitting the brakes in reverse relieves pressure on the torsion bar from lift. The stronger the bar the less distance it takes to unload. The reason weak bars are used for drag racing is they provide lift throughout their travel. Heavy bars lose lift and get looser at the the top.

When going forward and hitting the brakes the bushings are pushed forward. The strut rod is a pivot point between the spindle and the lower bushing.

Pull forward on the spindle it pulls out on the bushing. Pull back on the spindle it pushes the bushing forward. Add a swivel to the strut rod and you free up the motion and it gets worse.
Like I said take off the stabilizer link and pry the lower control arm back at the bushing. You'll be able to pry it off the pin. The only thing holding the arm forward at the bushing is the torsion bar and whats holding that forward??? The clip and without spacers and even then it travels 1/2 -3/4. Real stable set up. LOL . We tried with no luck

I like the adjustable strut rods just not used with lubed up poly bushings in the lower. Use the rubber molded in a shell.
We made are own struts before I bought a coil over suspension. We copied them off of "Ray Bartons Racings" Hemi Dart

My son was designing lower control arm with bearings for use with coil overs. We decided to buy a coil over suspension. Why re event the wheel. We went with AJE because of the light weight. For dual purpose or a heavy car I would recommend HDK. Stronger.

 

[go-fish]

 

[72bluNblu]

View attachment 1715858011 View attachment 1715858014

Just had to grind had to grind the plates and get new hardware. The plates were a little long. Also, the stamping of the k-member leaves a radius so I made a radius when I was grinding for fitment. The bolts were like less than grade 5. The end link bolts from Hellwig are 7” long leaving more thread than I want hanging under the lower control arm.

Yeah I put a radius on the ends of the plates. It would be nice if it was done by Hellwig but I wouldn't be entirely surprised if it wasn't necessary on all cars/K members. The end link bolts are also just left long, again probably a combination of allowing for tolerance and being a bit cheap on the production side of things. I ended up using shorter end links anyway when I went to the QA1 LCA's. I just ran the bolts, if I'd bought them I'd have bought better but they've worked fine.

Oh they’re tight. I actually think I need to back the strut rods off a hair. Which brings up a question. Do I need to have anything loose or backed off when going from an unloaded suspension to loaded suspension upon install? The torsion bar adjusters need to be backed off right?

Actually, since you have Delrin upper and lower control arm bushings you can torque everything before you set it down if you'd like. Because the delrin bushings rotate on the pins there's no need for them to be torqued at ride height like rubber bushings. The torsion bar adjusters may need to be adjusted to even up the ride height, but they do not need to be backed off.

That said, with your 1.24" torsion bars I would suspect that you'll only need about 1 turn on the adjusters past where the bolts make contact with the LCA adjusting lever to put your car at ride height. And since you're supposed to adjust ride height in the tightening direction when you set final ride height, you may want the adjusters fairly loose when you set the car down because of how little you'll likely need to screw them it to achieve your final ride height. Just one of those things from the service manual, you're supposed to raise the car to final ride height not lower it down to final ride height.

Hitting the brakes in reverse relieves pressure on the torsion bar from lift. The stronger the bar the less distance it takes to unload. The reason weak bars are used for drag racing is they provide lift throughout their travel. Heavy bars lose lift and get looser at the the top.

When going forward and hitting the brakes the bushings are pushed forward. The strut rod is a pivot point between the spindle and the lower bushing.

Pull forward on the spindle it pulls out on the bushing. Pull back on the spindle it pushes the bushing forward. Add a swivel to the strut rod and you free up the motion and it gets worse.
Like I said take off the stabilizer link and pry the lower control arm back at the bushing. You'll be able to pry it off the pin. The only thing holding the arm forward at the bushing is the torsion bar and whats holding that forward??? The clip and without spacers and even then it travels 1/2 -3/4. Real stable set up. LOL . We tried with no luck

I like the adjustable strut rods just not used with lubed up poly bushings in the lower. Use the rubber molded in a shell.
We made are own struts before I bought a coil over suspension. We copied them off of "Ray Bartons Racings" Hemi Dart

My son was designing lower control arm with bearings for use with coil overs. We decided to buy a coil over suspension. Why re event the wheel. We went with AJE because of the light weight. For dual purpose or a heavy car I would recommend HDK. Stronger.

View attachment 1715858366

View attachment 1715858367

View attachment 1715858368

View attachment 1715858369

And here we go again. The factory design rubber LCA bushings are not molded into the shells, it's a simple friction fit. And if you think a chunk of rubber will keep the LCA attached to the pivot pin, well, I have a bridge to sell you. The rubber isn't what keeps the LCA from moving around. Here's a deconstructed rubber bushing. Notice how everything came apart and there's no damage to the rubber itself. It's not molded or bonded to anything, which is why it can be slid apart.

The idea of the LCA pivoting around the strut rod is also laughable. The strut rod goes through a tube in the LCA with a pretty tight tolerance slip fit, and at an angle to the axis of the LCA. It will not work like a simple pivot point as you describe, the strut rod would need to be perpendicular to the LCA and not through-connected for that to be an issue or concern.

Did that happen with a drag car. I could see that with light T-bars and a car lifting the front end way up. Especially repetitively slower working it’s way out.

Or some other situation where the suspension was very unloaded?

Best of luck, but you can't logic OMM on this. Despite the fact that you've run poly bushed LCA's on road courses in excess of 100+ mph with much more loading than a drag car should ever see OMM still thinks your LCA's slide back and forth all over the place. He simply refuses to accept that poly and Delrin LCA bushings work at all. And you can forget trying to convince him that they work differently than the rubber bushings they replace, or that when properly installed they can work BETTER than the rubber ever could. He couldn't do it, so everyone else must be wrong. You should post up the picture of the alterations you made to your poly bushings to get them to fit properly, he also thinks you just "slide them in" and they work in all instances. Probably also why his failed.

View attachment 1715858430 View attachment 1715858436 View attachment 1715858440

View attachment 1715858431

Awesome!

Are those Howe racing upper ball joints?

 

[go-fish]

Yep. The tall ones.

Hey, I’ve got the Moog Camber Kit - K8243A eccentric bolts. Should I be us g regular eccentric bolts with the SPC arms?

 

[72bluNblu]

View attachment 1715858477 Yep. The tall ones.

Hey, I’ve got the Moog Camber Kit - K8243A eccentric bolts. Should I be us g regular eccentric bolts with the SPC arms?

Nice! I have FMJ spindles so I went with Howe’s stock height upper ball joints.

Yeah I just use regular eccentric bolts on my SPC UCA’s. I set the eccentric bolts middle of range and use the SPC’s adjustment to set the alignment. Much easier to use the SPC’s for adjustment than the stock eccentrics.

 

[go-fish]

Nice! I have FMJ spindles so I went with Howe’s stock height upper ball joints.

Yeah I just use regular eccentric bolts on my SPC UCA’s. I set the eccentric bolts middle of range and use the SPC’s adjustment to set the alignment. Much easier to use the SPC’s for adjustment than the stock eccentrics.

That’s what I was thinking. When I bought the Camber Kit bolts and the camber washers I hadn’t purchased the SPC arms yet. I think my plan was to use an arm that had bushing like Firm Feel’s.

 

[Ironracer]

View attachment 1715858477 Yep. The tall ones.

Hey, I’ve got the Moog Camber Kit - K8243A eccentric bolts. Should I be us g regular eccentric bolts with the SPC arms?

Do those give you any more adjustment than stock? I've seen they say +1.3°... about as clear as mud to me. Thanks!

 

[autoxcuda]

View attachment 1715858477 Yep. The tall ones.

Hey, I’ve got the Moog Camber Kit - K8243A eccentric bolts. Should I be us g regular eccentric bolts with the SPC arms?

Are those different that stock cam eccentrics?

The bolt hex can only get so close to the edge of the eccentric washer.

 

[Ironracer]

Are those different that stock cam eccentrics?

The bolt hex can only get so close to the edge of the eccentric washer.

Agreed, just didn't know if they shaved it a hair..

 

[autoxcuda]

Agreed, just didn't know if they shaved it a hair..

I don't know either. Have to measure. Or I could dig up a OE one and see if there's any room left.

The washer diameter has to be the same for all to fit in the frame shoulders

 

[Ironracer]

I don't know either. Have to measure. Or I could dig up a OE one and see if there's any room left.

The washer diameter has to be the same for all to fit in the frame shoulders

Hey, that would be cool! Thanks. I'm about to get the Duster an alignment (I hope, shops suck these days) I have the offset bushings, but if I can get an edge there also.....

 

[go-fish]

I can't make out what makes them different besides they don't have the flat side along the length of the bolt.

???

@Ironracer @autoxcuda

 

[Ironracer]

Sick K, by the way! It's looking great, and gonna be Tight! Great details!

 

[go-fish]

Hey, that would be cool! Thanks. I'm about to get the Duster an alignment (I hope, shops suck these days) I have the offset bushings, but if I can get an edge there also.....

Do you have upper control arms that are adjustable? If not I have those camber washers. You can get 2 more degrees of camber with them. I'll give them to you for half of what I paid.
Mancini Racing Camber Spacer Kit