i purchased an all pro front hanger with shackles for my 87 sas. i want to make my own hanger that drops the front mounts another 1" down in addition to what the all pro hanger drops them and move the mounts another 1" forward(2.5" total forward, and 2" down). i think the all pro shackles are 5" from eye to eye. how much longer of a shackle do i need to make roughly to accomidate the new front hanger postion?

the shackle will go throught the frame.

You will want to drop the shackle down the same amount as the spring hanger to keep the pinion angle and caster constant. What springs are you planning to run with this setup that require you to move the spring hanger another inch forward?

I dropped my front hanger 2.5" from stock, 3/4" forward (plus 2" forward fromt the rear spring swap - 2.75" overall) and I found that a 3.5" longer than stock shackle worked well (7" overall). I had tried running a 2" longer shackle and had bad death wobble problems. So as Harry mentions, as much longer as the drop, perhaps a bit longer, mine are 1" longer than the drop hanger, the AllPro's are 1/2" longer than the drop hanger:

Front drop spring hanger

Wide body front spring shackles

It really depends on what springs you plan to use, and how the perch area affects the caster/pinion angle of your axle.

And think about interference between the pitman arm and the tie rod. I was able to move my axle forward nearly 3" without moving the spring hangers forward, using Alcans (about 2" forward just with the springs). That was plenty for me. Are you planning on relocating the steering box to accomodate the way-forward axle?

yes im building the truck from a bare frame up. ill mount the box where it needs to be.

im using all pros springs all around. i just want to get a few more inches of lift without having to use a bl or blocks and want to do it clean. i needed some ideas

4 crawler posted some nice links...thanks dude

The reason I asked what springs you are running is because I am concerned that if you move the front spring hanger another inch forward you will have a poor shackle angle. You are somewhat limited as to where you can mount the shackle because of the body mount.

Some people have solved this problem by mounting the shackles below the frame instead of through it, such as David "DRM" Moore who posted above. If this is the way you want to go check out his website, which is posted in his signature. Note that most people running shackles under the frame use relatively flat springs as opposed to something like the All-Pro lift springs.

I'm running a 2" drop, 1" forward hanger with 2WD rear springs (axle 3" forward)with a 2" longer than stock banana shackle. Caster seems to be fine, no wobble. Keeping the added drop equal front to rear is the key.

would making a drop front hanger like DRMs hanger and using all pro 5" springs be out of the question? ( i orderd 5" springs)
is mounting the shackle under the frame that much better? i was under the impression going throught the frame is the way to go...

i guess im just looking to lift the truck enough to clear 38s without a problem and didnt want to get hoakey.

i like drms hanger but maybe that 3" along with the 5" springs will be too much for a trail truck. how will i know how long to build the shackles to match whatever front lift the hanger adds?

thanks a ton guys <img src="/forums/images/graemlins/cheers.gif" alt="" />

As mentioned above, you basically make the shackles that many inches longer than stock. In my case, I did 2.5" hanger drop and shackles 3.5" longer than stock (I added 1" for a little more caster angle), they ended up 7" center-center length. Or, the AllPro hanger is 1" drop, their shackles are 1.5" longer than stock. You do want the shackles *at least* as much longe as the hanger drop, a little more is OK, a little less is bad news.