K Frame Engine Swap Questions

[John Be]

I have a 1970 Barracuda that came with a 318 & SB 727, now it has a 360. I want to put in a 440 & BB 727 trans.

The stance I want is a little lower than stock. I want the rear 1/4 panel sitting about an 1" below the tire.

I was told to keep the OEM K Frame which will help with the stance I want. I do not know if that is true, since this is my first Mopar.

Do I change K frames or do you keep the one I have for a 440.

What is needed for the conversion??

Thanks!

 

[moparleo]

There is no conversion. The K-frame will accommodate both the Small block 318-340-360 engines as well as the 383-400-440. The 318 did not come on a 318 so something has been changed in the drivetrain some time in the past. As far as the ride height is concerned, the front is adjusted with the torsion bar adjuster bolts. The rear height will depend on the tires diameter. Before you start to mess with the rear suspension you need to choose your tires. The rear height is not adjustable so you will need to work with the springs and/or blocks. Or go airbags. $$$

 

[Adam]

Same K frame will work, but you will need big block brackets, if I recall. The front end is adjustable by turning the torsion bar adjustment bolts to raise or lower the front. A 440 is much heavier than a 360 you should upgrade to big block torsion bars. The rear is not adjustable without changing/modifying the leaf springs.

 

[John Be]

moparleo- What do you mean "The 318 did not come on a 318". Glad to know the K Frames are universal.

Adam-Thanks for the Tip Off on the torsion bars, I then should get BB torsion bars. Where are they available?

 

[340challconvert]

moparleo- What do you mean "The 318 did not come on a 318". Glad to know the K Frames are universal.

Adam-Thanks for the Tip Off on the torsion bars, I then should get BB torsion bars. Where are they available?

I picked up the Mopar Performance .92 bars for an upgrade on my 340 Challenger from JEGS. Paid 240.99 for the pair with free shipping. (P5249157) These were the factory 440/426 torsion bars.
My A66 Challenger had the factory HD .90 bars (factory size for the 340 and 383-4 cars) I was looking for a reasonable upgrade (ride and handling). You could go larger if desired.

 

[gdrill]

He may have made a typo and meant the 727 did not come on a 318, indicating the trans was also changed with the engine. Doesn't matter though as you are going big block anyway!

 

[John Be]

paharamie-Thank you for that info!
This is my first time dealing with a Mopar, so everything mentioned is a lesson for me.
If I understand, the Torsion Bar also raises and lowers the car besides the soft to hard ride adjustments?
Once they are in place, can they be fine tuned. Say if I stick a set in like yours, but find the car is raised a little too high, can a turn back on the bar to lower and do they have a locking mechanism if the desired height is found.

 

[340challconvert]

There is also a process for installation and adjustment of torsion bars.
- Always adjust the bars with the weight off the car.
- Adjust the bars, do not torque the LCA and UCA bolts until you get the car at the proper height. Tighten everything after the final adjustment.
- Bounce the front end after each adjustment to let the height settle. There are factory ride heights listed in the factory manuals.
All of this would have to be done following the installation of your big block which will be heavier then a small block

John,
When you get to that point, pose your questions to the members here who are always willing to help out.
Do some reading on this topic on many of the posts here at FEBO. I am still learning new things myself.
Good luck with your project.

 

[John Be]

OK Thank you!

 

[gf7cuda]

Paharamia, good info!

 

[Adam]

Summit, Jegs, Mancini racing, Firm Feel, and PST sell the bars.... In my 440 Challenger I went with the 1.02 bars, if I recall. I like them a lot; I think you will need the heavier bar if you plan on lowering the front end. Btw, the factory bars had a protective coating on them and some of the aftermarket ones do not, you should at least paint, or spray them with a non hardening under coat or similar product.

Here is a related thread: Best bang for buck suspension upgrade kit?

 

[John Be]

I now have a good ideal on what I have to do.
Great information everyone, Thank you!

 

[moparleo]

Thanks for the edit correction gdrill. Exactly right. Of course he will also need a different radiator, engine harness, (larger diameter fuel lines) my advice. If it did not come with a sway bar or disc brakes, now is the time.

 

[John Be]

Why would I need to replace the engine harness, I will be going with pointless ignition?

In regards to the K-Frame engine mounts, for my understanding, did they make specific K-Frames for sb & bb's?
By adding BB brackets to what I have a band aid way of doing it ,or is all K-Frames universal?
Thank you!

 

[John Be]

bump

 

[Litchkar]

I went with PST 1.03 torsion bars, they were powder coated and are a nice upgrade. The bars available now are much larger than OEM ones, and improve the handling. I also installed new torsion bar adjusters, available as a kit with boots. PST give For E-Bodies Members a 10% discount too.

 

[Litchkar]

Just a thought, look at the lower control arm rebuild kits, they can help remove some of the flex found in these front ends, a reasonable upgrade if you have access to a welder.

 

[evenflow]

small and big block k frames are the same. can also change rear height with different rear shackles

 

[sportster2000]

Why would I need to replace the engine harness, I will be going with pointless ignition?
Thank you!

There will be minor difference in the location of items between the two harnesses. If you do not swap to a BB harness then you will have to make extensions for the harness to reach the items. I had to make extensions for the water temp, electric choke, and distributor on my car since an engine harness for a BB was not an option.