[redz 1970 K5]

Good input from above.

My $0.02 (1/2 off sale now for $0.01)-


SPRINGS-
I have run Tuff Country 6" springs on my 71 K5, Skyjacker 4" springs on an old ford and now 6" BDS springs on my 88 Burb. I have been VERY happy with all three.

I would really only avoid any HD springs and you should be fine. If it says HD, you definitely don't want it. A stiffer ride of the HD springs just isn't worth it and is borderline bone jarring.

BRAKES
Most kits come with front brake line relocation kits, which moves the mount from the frame to below the frame. They work fine and are perfectly acceptable and safe, but you can also pick up extended stainless lines and keep the stock routing.

STEERING
For 4", the standard raised steering arm works fine. I tend to think that a raised steering arm is almost borderline for a 6" though, because it still keeps the drag link at a slight angle. If your drag link ends are pretty worn out, I would probably go ahead and do a 2" drop drag link along with the steering arm- that way you get steering correction AND new ends. I would go ahead and plan for a single steering stabilizer setup too. They work wonders with larger tires.

NOTE- Be prepared to take the driver side knuckle out and take it to a shop for the removal/replacement of the steering arm. It's worth paying $30 for a shop to do this. This can be the very hardest part of the lift, and I am not kidding. Those little tapered cones will NOT come out without a fight, and the older the truck the harder the fight. If I had to pass on ONE piece of advice, that would be it. I spent a good 6 hours with the help of a neighbor torching, cutting and hammering with no luck. The machine shop couldn't even press it out!!! They had to cut it off and replace the studs!

DRIVETRAIN
A good alternative to keeping everything happy (if it's available for your truck- I am pretty sure it is) is a transfer case drop kit if you need it. It will drop the transfer case down by around 1" to help with the angles. The rear driveshaft won't even be an issue. Even on my super short wheelbase K5, the rear shaft was fine. As a matter of fact, my 71 K5 didn't even need a thing when I put a 6" lift on it. This is a case by case basis I guess.

Hope it helps.