What are the longest shackles you would use with factory springs. I have a 87 truck on 87 runner frame. The rear sags a little and was hoping to get a little more flex out of the stock springs. I do plan on a lift I just want something to get me by for a while. Heres a pic after wheelinthe other night. Thanks, Jason

[IMG][/IMG]

 

Can use as long a shackle as you want. I've seen some long ones too, but shackle length will effect pinion angle, which if extreme enough will cause D-line vibes and part wear. Forget the calculation for the average angle change to shackle length.

 

I have some 6in long shackles made up now I just dont have them on yet. Stock is 3.5in. I figured I will proably only see 1.25in lift out of it, which should put me back at stock height befor the springs sagged. I ddidn't know if I went too long the shackle would loose too much angle and not perform as well.

 

http://www.4crawler.com/4x4/CheapTri...line-101.shtml I'm not talking about shackle angle. Think back to HS geometry, angles and coangles i think with luck some one else will hop onboard and point us both into a better explanation and we'll both learn something.

 

I knew you didn't mean shackle angle. I was just saying that they were my first concern. I never thought about driveline angle thanks for pointing that out,