Basic suspension lift question (89 Burb V2500)
 

A "suspension lift" usually involves larger leaf springs and a block that goes in between the axle and the leaf spring. So what people call a "4 inch lift kit" amounts to larger leaf springs and a block that, when installed, add approximately 4" of additional height to the rig. CORRECT?

On the other hand, a "shackle flip" kit actually replaces the rear spring shackle with a new unit that reverses (flips) it. The end result of a "shackle flip" is an increase of overall height of the rig, usually in the range of 4". CORRECT?

A "shackle flip" is considered superior to the usual "4 inch lift kit" (larger springs and blocks) because it involves greater stability/flex and overall sturdier construction and better handling. CORRECT?

Reason I'm asking: my 89 Burb 2500 (3/4 ton) has a block lift. I think it is a 4" lift, but when put on a 3/4 ton truck, the end result is probably more like 6". It frankly is a bit more than I want/need, as far as overall height and driveability.

SO: what happens if I get rid of the blocks and put on a shackle flip? What do I need to do to be sure that the rear axle ends up at the same height as the front axle?

Sorry for the "noob" questions and thanks for all input.

Re: Basic suspension lift question (89 Burb V2500)
 

The leaf springs aren't necessarily larger, they just have more arch to lift the vehicle. True that a suspension lift might use springs with more arch in combination with lift blocks. A shackle flip does give 4" lift and people say it does ride better and work better off road. Can you post up a picture of the truck?

Re: Basic suspension lift question (89 Burb V2500)
 

Pic 1 is a standard stock shackle

Pic 2 is a DIY flip shackle

Pic 3 shows what happens to the rear pinion when you install a shackle flip - it gets moved up and changes driveshaft geometry / internal lubrication. On a 4" lift it may or may not create a vibration - meaning you may or may not have to adjust the pinion angle back down with a shim kit or re-welding the perch. It may also cause the pinion bearing to get less lubricant - although I've never seen a problem with that.

The flip kit improves articulation and is supposed to improve / eliminate any rear axle/wheel hop.

More answers to your questions: http://www.offroaddesign.com/catalog/shacklekit.htm