Shackle question

[HeavyMetal72]

Got a question about shackles. I am doing a frame off on my 72 K5. I am at the point where I am putting it all back together. I am putting a D44HD and a 14 bolt underneath on a 6 inch spring lift up front and a 4" flip and 2" springs in the back. The spring perches are off the rear axle and can be welded into place to adjust the pinion angle. I have a set of 4 and 6 degree shims for the front. I am planning to put the 4 degree shim on the front axle to start. Because I need to get the frame rolling asap, I want to set it up as close as possible to the correct pinion angles. I am probably jumping the gun, but the engine, trans and transfer case are not in any condition to drop in the frame to help with the mock up. Anyway, to the meat of the question.......doing some reading online. I see that alot of fabricators recommend replacing the front shackls with shackles that are up to one inch longer to help keep the spring from contacting the frame. Seems to me that a longer shackle would add to the pinion angle problem created with the addition of 6" lift springs. I'm not going to weld the rear perches in place until the drive train is installed, But I still would like to get as close as I can. Any thoughts would be appreciated as well as any insight from anyone running a similar set up.

 

[70jimmy]

I have 6" tuff country ez rides in front, extended shackles, 4 inch flip in rear with 3 inch lift springs and with my cage and tire carrier I had major butt sag so added super shackles and a zero rate to the rear and now its level to just barely sagging, so I would say be ready to add some to the rear to level later. the rear springs will sag more than the front because of the difference in arch.

I don't know if I would have needed the extended shackles or not but mine were worn out so i replaced them. Also stock mine had a piece of metal on one side of the front spring to prevent it form compressing too much ( the shackle moving forward too far.

I will look to see what angle shim I used on the front, seems like 6 or more. I bolted everything up on the rear and clamped it together using the u bolts and played with the angle till I had it right then tacked it then took it apart and full welded.

 

[HeavyMetal72]

Thanks for the info. Since I haven't ordered the rear springs yet, I guess I'll go with more lift, maybe 4". I'll start with the 6 degree shim up front and adjust from there if needed.