Yep you can do it in the rear and its no big deal if you don't go crazy with it and your leaf springs are in good shape (unlike mine). I've had my blocks for a while and can't decide if I want to put them in. I think that you don't to put them up front because you wouldn't want the springs to slip off the blocks. Or something to do with axle wrap.
I had a 79 K-10 Chevy when i was a kid and i bought a homemade liftkit from a guy for $30.00 which consisted of 4 blocks and longer U-bolts and thought that i got a good deal until i installed it. The first time that i drove it down the road it was all over the road especially if you hit a swag in the road, it would really throw you around.You have to have more leafs up front to stiffen it up.:no:
Lift blocks are evil, not to mention illegal when used on a steering axle in accordance with DOT (and probably your state and local laws).
The problem with lift blocks on a steering axle is they tend to sway. Lift blocks arent designed to withstand side forces that are placed on them whenever the wheels are turned to the sides. Sometimes they respond by swaying back and forth and making the vehicle uncontrollable, and sometimes they collapse and the front axle stays put while the truck tries to continue over the axle.
Lift blocks apply leverage against the springs when torque is applied to them (ie when you press on the gas to take off). On the rear this is realitively minor (compared to the front), you get axle wrap which causes loss of traction. If the springs are older you may get enough movement to spit out the driveshaft. And if it's a real bad day you'll spit out the lift blocks and axle, causing body damage as the rear wheels try to go through your rear quarter panels.
Save your money and lift your truck the correct way, with springs.
You can also lift the truck with shackles. Shackles are usually as inexspensive as blocks, but shackles have issues also. They cause the truck to sway more and on older springs they cause the spring to wear much faster and sag.
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