how long is the drive shaft and what rear axle are you running?

When I did my drivetrain swap I made sure I had plenty of rear driveshaft length, something like 28" IIRC on a YJ with stock wheel base and about 7-8" of lift in the rear

 

It is 21" long and im running a 9"

 

It sounds like your going to have a few options:

-swap your auto for a shorter manual trans
-run a high pinion rear
-lower your ride hight
-legnthen your wheelbase
-run a high angle double caron

That 9in has a way low pinion, so that is most likley your biggest problem.

 

Where could one get a high angle double cardon? And how much?

 

Tom woods and High Angle driveline were the first two I could think of.

http://www.4xshaft.com/index.html
http://www.highangledriveline.com/

Neither of them list prices on their site so you will have to call for a quote. It may be expensive, but it will most likley be the cheapest way to go besides lowering your ride height.

You can also run your springs backwards to get you about 1.25 more driveshaft since the centering pin on a yj leaf pack is not centered.

 

Actually the center pin is centered. And I noticed the offset ujoints on tom woods website. How much vibration do these actually put out. Could it be street driven (10 miles at the most)? This may be my ticket out.

 

Actually the center pin is centered.

Hmm, my stock 91 YJ springs were not and neither are the RE 4.5 springs I have now.

But anyway, That offset u-joint will not work in your double cardan unit, but I do not see why you could not use it in place of your double cardan set up. I have heard alot of people say that they do not last, but I have no experience to support this. In reality, a double cardan joint is not made to provied more angle, but less vibration. I would think that you will get quite a bit of it with a single cardan like that though.

 

http://www.pirate4x4.com/forum/showthread.php?t=814964&highlight=leaf+spring+chart

Why wont it work with the cv i have now?

 

The part of the DC that serves as the mounting point for the driveshaft (forgive me, I can not remember what it is called) has to engage the centering ball within the coupling yoke and also serve as the seat for the u-joint that is on your rear output. With a offset u joint, all four caps will not be able to be in their proper seats and allow the centering ball to set into place.

 

yeah I realized that after I had posted. Im going to try to grind on my cv first then if that dont work im going to try a single joint with an offset u joint.

 

My TJ is leaf sprung in the rear, Im running a cut down XJ front shaft. Cheap and works well!