My buddy owns an 01 gmc extended cab 2wd and when he did his spring swap for towing a huge boat in the front he used f-250 coils in his from an aftermarket dealer. This was about two years ago and the springs were the same part number for a 01-04 superduty. The diameter of the stock springs and the f-250 springs were so close we couldnt tell the difference. I dont see why the jdm ones would be any different. Wouldnt the only difference be the poundage on the spring itself and the diameter of the coils theirselves?

Unless the f-250 springs are a bigger diameter than the f-150, jdm, v6 springs???? Foose i am planning to raise my truck up a bit by buying new drag springs and cutting them less than the ones on the truck currently so if i get that done before you get back you are more than welcome to mach up my jdm drag springs that are on the truck or even use them if you wanted.

Hmmm... Good to know and that sounds great that he was able to run the f250's.

About the springs, that's a generous offer and thanks, but I think if I do this I want to run the spring full length and get the correct lower control arm to achieve my ride height. Anything changes though I'll shoot you a PM about trying/buying.

Thats what I would do.

No problem just trying to help out. Should be a PITA figuring out everything exactly but once it is it should work great.

Make up your mind, yesterday you sya cut em and run em

There are no readily available lowering control arms that I would trust on my truck. So cut your coils unless you plan on buying the stifflers LCA's.

http://profile.ak.fbcdn.net/hprofile...199_8714_n.jpg

I cant see the pic at work but Im sure its funny. Heres the guys site.
http://buystifflers.com/1999to2004.aspx

Well the V6 springs I ordered last week before this idea came along came in. Had the lady send me some pictures. Not excited about them sitting of the wood floods, but any case. Cat seems to think their suspect as well lol.

She measured them at 16 1/4 tall, 5 3/4 outer diameter, 4" inner. Weight together is 31 pounds.

Spdracr0, any chance you could bother you to take those measurements on those JDM's before you install them?

http://i152.photobucket.com/albums/s...91/photo89.jpg

http://i152.photobucket.com/albums/s...91/photo90.jpg

http://i152.photobucket.com/albums/s...91/photo88.jpg

^^I'm sure if you mentioned them being on the wood floors you'd get the ol "well you wanted me to take the picture!"

Have her hold the springs later and you take better pictures.

Pictures should have been taken in the kitchen.

I also run the JDM springs. It is too bad that we have to cut them for proper ride height. But the Stifflers adjustable height lower control arms should soon solve that issue. The springs do work well, and with good adjustable shocks are quite streetable.

Foose, I would not worry about the Caltracs. Most of the fastest leaf spring vehicles are on Caltracs.The ones for the Lightning application are a compromise due to exhaust interference issues. That's the main reason they don't work right.


Jim

Ive never seen exhaust interference issues on the several L Ive seen them installed on including my own. Yes they are on some of the fastest cars. That being said Im not saying he cant get them to work Im just suggesting a route that I think is easier in the long run.

Update, I got a hold of Jim over at JDM. He said he couldn't say yes or no on fitment and directed me to R&H in New Jersey who builds them. I then called over there and spoke with Frank Jr. for a good bit. He wants to crunch the numbers and come up with something that will be setup for the GM camp. So, that's all good news and thanks again for the help up to this point. I'll keep the thread updated on what develops.

As for the Cals, I know they work well on cars but are also designed to be on a Mono Leaf setup. I've removed my overload, and run a dual leaf setup. I've thought about going down to a single, but I still tow the boat. Did you guys try to run them with 3-4 leafs? If so that could be some of the reason they don't work as well.

There is also a long list of other things they can make them not work if not setup right. As for now, I'll see how far I can go with them with a new springs up front. I really think a mid 1.4 will be possible, but I like being optimistic. :cheers

That is because they compromised the geometry to prevent the interference issue. Regular F150 setups are much different.


Most Lightning guys have avoided these due to poor feedback and the fact that simple long bars(torque arms) work so well for us. But the Hotchkiss leafs are the ones most often used. I believe they are 2 leaf.

Caltracs WERE NOT designed around a mono leaf setup. It doesn't hurt to have a split mono setup though. It also doesn't hurt to have leaf spring sliders also. One good part on top of another just progressively makes your suspension work even better.

And if you do go to a mono leaf setup, I would NOT do it on stock leaf springs. That will make everything worse. Ride will be horrible, load rating will drop, and ride height will be adjusted also. Just a plain bad idea.

If they make a split mono design than yes go for it (you could still tow I am sure). But with my search I do not see a split mono setup for a fullsize silverado/sierra. Probably because many have not shown interest to manufacturers to produce such item.

What shocks do you have in the rear? are they adjustable. I may have overlooked that piece of information.

Thats what I use. :bigthumb:

I do have single way adjustable on the rear, 90/10's on the front. When I said the Cals are designed around single, I mean Calvert Racing recommends mono split leaf setup, sell mono split, and from reading on YB most car guys going very low 1.x are mono cars.

I think the rear is working ok right now and agree running a single would change a lot of things going on back there. I'm ready to swap springs up front, new A arms, and maybe shackle the rear to bring the over all stance level.

Didn't read much on the leaf spring sliders other then seeing some pictures. How do those work?