hey i have a pretty stock '81 Toyota pickup on 31s right now but I need to replace the shackles in the front so I thought I might as well do them in the back as well. I'm going to pull the box off and don't mind cutting fenders. I know trail gear sells up to 6". how much lift could I get from just shackles( want to run 33s).

 

New shackle minus old shackle length = lift added.

 

yeah that's what I thought, is it better to go with the kit or should I just buy the plates?

 

Lifting with just shackles can cause driveline vibes in rear as it can effect pinion angle. The vibes will happen more as speed is increased depending on angle.

Front shackle lift will also effect pinion angle but more importantly steering geometry, castor. Depending can cause a death wobble.

Your rig, your choice. Do some research and be cautious of free advice.

 

If I recall there are 2" lift shackles but they are pretty long. I would add a leaf instead.

 

Why do you need to replace the shackles?
They are generally pretty durable.

For every 1" increase in shackle length you gain 1/2" lift

 

that's what I thought but I checked and one on the driver side is snapped and the other is missing.. leaf is literally resting on the frame.

 

To give you an idea of what a little extra shackle length can change. When I rotated the pinion to run dual case with a cv driveshaft. You know short wheel base and dual case. When I first rotated pinion I listened to advice and set the pinion angle 2* below t-case. Well this caused vibes in driveline between 65-70 mph. I added 1/2" longer shackles to rear, it raised the pinion so it points straight at t-case now. So 1/2" is about 2* of course only as accurate as my angle finder.