Topic: shackle and hanger tech q's

[yotadork83]

i am doing a rears up front and i have never done this before and dont want the caster angles to change so just a few Q's

1: if i lengthen the shackles i need to drop the front hanger the same distance right?

2: on the driver side i need to add a 3/8 think plate to the spring pearch?

3: should i move the front spring hole forward? if so how much?

4: and i am making flat shackles and was wondering how thick to make the spacers?

[79coyotefrg]

i really  dont like the concept of  long shackles  on the front axle 

and i think you will need to add a leaf from like a ford pack  to the rears  or  they will sag

[Hyena]

1. yes you will want to drop them about the same distance

2. about that thick should be good.

3. yes move it forward.  maybe 1 to 2 inches minimum.  i kept mine in the same spot but dropped 2 inches and i hit my tubbed firewall with 37's still.  so you will want to move it forward more.

4. not sure on the sahckles.

[6.72:1]

The spacers should be 3/4" thick.

I too make flat shackles and had an '83 once.

[yotadork83 [OP]]

cool thanks i am making longer shackles only about 1.25 longer than stock

[RRMike]

I'm not so sure about the shackle thing.  I hear people say that and it's not entirely correct IMO.  The longer shackle is because the spring is longer and you will be riding around with the rear eye of the spring up against the frame and kink up your springs on compression.

What will actually happen when you put the longer shackle on is that the shackle will be sitting at more of an angle due to the length of the spring and the spring eye won't actually be much if any lower from the frame than it was stock.  I would look at it now and see how low the spring eye is from the frame with the stock spring/shackle setup and then check it out when you put the new shackles and springs on.

I put 6.5" boomerangs on mine and it was fine.  With the longer 48" rears they were folded back far enough that the spring was still nice and tight to the frame under compression and not much if any lower than stock at static height.  I have since lowered the hanger (to get the springs further from the pitman arm not to correct caster) and it seems to wobble a little bit now and it didn't before with just the longer shackle and springs.

[RRMike]

Also you might want to make the shackles a bit longer than that.  You can always drill new holes and cut them shorter if you want later.  I think the springs are 3" longer than the stock fronts.  On a side note if you run straight shackles then may hit the body mount behind the shackle tube so you might have to notch it while you're at it.