I read here on your site the article:
Driveline Basics with Steve Johnson. After looking at my truck (1980 with 8" suspension lift) it appeares that my pinion angle might be more that Steve indicates is recommended (3deg)I don't wanna put any undue strain on the driveline .....he says shims are a possibility....
My question is is it possible to put slightly longer shackles at the front of the leaves and shorter ones at the rear of the leafs??? this would rotate the diff a bit I'm thinking.....

anyone tried this? what are the drawbacks or pontential problems????

Anyone?

Shackles on both ends of the springs??? Sounds scarry to me. Usually people us shims or reposition the spring mounts on the axle.

Where in Canada are you?

you could use a new front hanger which will drop the front of the springs down an inch or more, shorter shackles like stock length would improve it as well, no shackles on front hanger though...this would require welding for the front hanger.

If you do this to the front axle you will likely end up with negative caster, which leads to wandering and less return to center of the steering wheel. The best solution is to cut and turn the knuckles .

Yes, on the front axle, you can use shims to correct up to the limit of the steering caster angle:
http://www.4crawler.com/4x4/ForSale/Shims.shtml#FAQ1

Beyond that, either live with the pinion angle you have, which is fine as long and the u-joint does not bind and you don't need 4WD at high speeds. Otherwise, you'll need to cut and roate the steering knuckles as noted, or install a dual transfer case or a high pinion front diff, both of which can greatly lessen the front driveshaft angle.