"Leaf Springs Don't Flex" 

Honestly the setup doesn't work very well on the street - the front half of the spring is very short and makes a steep angle, giving poor break dive characteristics. As well the combination of the slinky spring and long shackle makes the axle underconstrained side to side. I'm going to be replacing this setup with a leading arm 3 link and airbags at some point, I may make a video about it.

@@msbmotorsports I am in Colorado Springs and have a 83 myself. I have had many after market suspension types and they all brake dive like crazy Trail Gear, All Pro, my buddies home made CAD links. I am just saying I would love to see before you change it. If you can find it in your heart to help a fellow old toyota nerd, BTW this is my 15th 80's toyota so lol.

How did you end up choosing the 54" gm leafs? What car did they come off of? I'm in the process of installing the 63s on my 87 4runner and I am trying to figure out the front (sold front axle). Everything I've read says to install the rear leafs in the front. But mine are broken

@@jesusakadice 1991 v20 suburban rear leafs. I’m sure other square body trucks use 54” springs too.

It's in the description my friend

@a1gemmel

If you requested me I think I fat-fingered it away😆

thanks you too!

Why?

@@msbmotorsports its pretty close to 90*. There's a bunch of info on YT for it. Probably super stiff in the back rides like a hay wagon. I had to do a shackle relocation to mine, much smother ride and way more flex.

@@Jon-ko3vv You would be right if it had a highly curved spring like the toyota. However it has a flat spring that hardly changes length over the range of articulation, you can see this in the video. In this case, a shackle near 90 degrees to the frame is fine and does actually provide the softest ride. The measurement I consider important with shackle geometry is to have the angle between the shackle and the thrust direction of the leaf (typically along the length of the spring near the eye) to be 90 degrees so that as the spring pushes or pulls on the shackle, no portion of the load is transferred through the shackle as a compression or tension force.

@@msbmotorsports 👍