55.2-59 C4 IRS on a 55-59?

[Kevin_C]

Ive been going back and forth on suspension lately and have been leaning toward doing C4 suspension with Flat out kits. The front seems pretty straight forward an looks to give a similar ride height to what I have now. When it comes to the rear I had bought a 8.5" 10 bolt posi and was going to do a 4 bar to give myself ride height adjustment. Recently I started looking at the C4 IRS and there seems to be some pro's and con's. Don said his kit gives a 1" rake front to back which would increase if you do staggered rims. I was thinking 18's and 20's but could do 18's all around. I would like to keep my truck fairly level. I've seen some that have a great stance and some that are higher in the rear than I like. I spoke to a local vette yard and they told me $500 for a front and $1000 for a dana44 rear. I'm going to be shortening my frame soon and figured I would do the rear suspension at the same time.

for those that have done IRS on a Task Force I have a few questions:

1. would you go with the newer wider rear or the older narrower setup. Im planning on a little over 400hp stick shift so it will be a Dana44 regardless.
2. How does the ride compare a 4bar. I like to hit the corners but probably going more pro-touring than auto-x
3. did you do anything to adjust ride height? Shorter coil overs, or shifting mount brackets etc?
4. Any difficulty with rim offset?
5. Would you do it again? I'm sure I could easily sell the rear end I have in the shop. For me the c4 solves the rear disc and parking brake issue from the get go but the IRS adds more moving parts.

Anyway I would like to hear what you think or susgestions you may have.

[dsraven]

if you are going to shorten the frame and plan to lower and cnotch it then you might as well just lop it off ahead of the rear axle and fab up a step notch from some rectangular tubing, add some frame rails behind the axle and some cross members, raise the bed and be done. better than cutting the frame behind the cab and then building a suspension with a c notch, because the truck is lowered, and then finding out it bottoms over bumps and you need a deeper c notch.
just my opinion.it does seem that a lot of guys cut the front end off to weld on the clip from another vehicle, then cut the frame in the straight middle section to shorten, then do a c notch or step notch behind that. the frame has been cut and welded how many times then? wouldn't it be better to shorten and step notch in the same place?

[svr]

I used ‘88 C4 on both front and rear of my ‘57, i made myown brackets and cross members. Cant answer the ride question as mine is not on the road yet. I am useing the C4 leaf spring in the rear of mine and made it all sit withonly a slight rake. I had to make the toe adjustment arms fit under the hub arm on the outside to get frame clearance and make longer spring bolts to get the ride height i wanted. As far as rim offset goes when tried to use the C4 ‘88 wheels i had to put a 1 1/2” spacer on each side so the 285x17 wheels would clear the dog bone mounts on the frame. That made them clear the fenders about right but i had to mini tub the bed then to get clearance on the inside with the 10” rims and the 285 tires. In the end i was able to find a set of torque thrust 2 rims off the shelf with the proper back space so i didnt have to use any spacers. Hope that helps.

[Kevin_C]

I hear what you are saying dsraven but unfortunately its a bit beyond my abilities. I can weld Basic things but when I shorten the frame my plan is to square and level it and tack it into place and will need to hire a mobile welder to do the final welds and plates. I had thought that with the flat out kit the frame didn't need to be notched. Can anyone confirm that? I know they sell a flip kit for the tie rod ends but wasn't sure if I would need that
SVR thanks that does help. I read through your build and it is well done. If i go IRS I will use the flatout kit with the coilovers. With the leaf you can just get longer bolts to lower. I think I may have some options when ordering the coil overs to help set ride hight. Im not looking to completely slam the truck but im trying to keep it close to where it currently sits with the drop power Ibeam and lowering springs.

[58CameoAZ]

I have the Flat Out Kit front&Back on my 58 Cameo ( Does not Require the C-Notch)

I went with the Aldin Coil overs that Flat out suggested at the time

Like SVR, my truck is not on the road yet.

I am very happy with the kit, I did re-position the front crossmember as my truck is 2"
longer as its a 58 (Kinda found this out the hard way, tho it was my fault and happy were it is at now)
Good Luck with your Build!
Allen