What mods needed for 4" lift?

[Pender1]

My plans changed a little and I'm now going to be getting a 4" lift instead of the 2" that I had planned. I'm trying to determine what I'll have to modify to do a 4". I know moving up to 6" means you have to go to crossover steering, but I'm not sure where the line is on some of the other stuff.

Here are the things I'm questioning:

-brake lines (will a relocation bracket work or will I have to buy extended lines?)
-drive shaft (is it long enough?)
-sway bar (do I need to put in drop spacers?)
-pinion angle (how likely am I to need to shim it?)
-TC drop?

Am I missing anything else? I'm going to be running 33x12.50x15's on a 10" rim.

 

[skysurfer]

-brake lines (will a relocation bracket work or will I have to buy extended lines?)
-drive shaft (is it long enough?)
-sway bar (do I need to put in drop spacers?)
-pinion angle (how likely am I to need to shim it?)
-TC drop?

I bought extended stainless lines. The kit came with extender brackets but they didn't do any good.

On my Suburban the d shaft was fine in stock length.

I made drop spacers for the front bar. It would have worked without them but the angle was a bit wonky. The flatter the bar the better.

Didn't bother with pinion angle. Thirteen years later and still no problems.

The kit came with some spacers for the transfer case.

Be sure to get the 4" drop steering arm.


Only mistake I made was doing the lift in the garage without checking the height of the header for the garage door. Had to roll her out on flat tires.

 

[77 K20]

I bought extended stainless lines also. Yours are 31 years old- not a bad idea to replace them anyway.

On a long bed truck my drive shaft lengths were ok.

Spacers or remove the front sway bar. The flatter it is the better the ride. A lift makes the sway bar tip downward at an angle. Then when you hit a bump the axle moves up and tries to "compress" the sway bar. That's impossible- so it rides very rough.

Pinion angle- I just used lift blocks and they have a bit of an angle to them. Never had any issues.

I didn't drop the transfer case.

I 4" drop steering arm was fine in most cases. If you off road and articulate the axles around a bit then you can start getting some steering issues.

Other things to think about:

With a half ton and larger tires look into getting a steering brace on the frame.

Longer bump stops for the front axle.

 

[bucket]

These two fellas nailed it. I also prefer going with extended stainless brake lines, I have also found that the sway bar does basically nothing and it doesn't hurt to just remove it.

 

[Pender1]

I bought extended stainless lines. The kit came with extender brackets but they didn't do any good.

On my Suburban the d shaft was fine in stock length.

I made drop spacers for the front bar. It would have worked without them but the angle was a bit wonky. The flatter the bar the better.

Didn't bother with pinion angle. Thirteen years later and still no problems.

The kit came with some spacers for the transfer case.

Be sure to get the 4" drop steering arm.


Only mistake I made was doing the lift in the garage without checking the height of the header for the garage door. Had to roll her out on flat tires.

The kit I'm looking at comes with the drop brackets but I'll probably just buy buy some extended stainless lines for good measure. The kit also comes with a drop steering arm so I'm good there. And I'll be installing this at work with 15ft+ roll-up doors, so I think I'll be ok on clearance.

I bought extended stainless lines also. Yours are 31 years old- not a bad idea to replace them anyway.

On a long bed truck my drive shaft lengths were ok.

Spacers or remove the front sway bar. The flatter it is the better the ride. A lift makes the sway bar tip downward at an angle. Then when you hit a bump the axle moves up and tries to "compress" the sway bar. That's impossible- so it rides very rough.

Pinion angle- I just used lift blocks and they have a bit of an angle to them. Never had any issues.

I didn't drop the transfer case.

I 4" drop steering arm was fine in most cases. If you off road and articulate the axles around a bit then you can start getting some steering issues.

Other things to think about:

With a half ton and larger tires look into getting a steering brace on the frame.

Longer bump stops for the front axle.

I'm planning on getting a brace from ORD for the steering box. How much bigger of a bump stop would I need? I'm planning on some light off-roading, but nothing serious. May be going to Uwharie later this year.

These two fellas nailed it. I also prefer going with extended stainless brake lines, I have also found that the sway bar does basically nothing and it doesn't hurt to just remove it.

Would removing the sway bar hurt my drivability? This isn't going to be a DD, but it will see a good amount of around town driving.

 

[77 K20]

http://offroaddesign.com/catalog/bumpstops.htm

I think on my current truck I ordered the 4.5" ones. I think the stock ones were 2" or so and I put a 3" lift on this truck. Basically try to extend the bumpstop down about the same as the lift to keep the springs from compressing too much in case of a huge bump and either breaking the spring or bottoming out the front shocks. The front shocks are so short to begin with when you get longer ones for the lift they can collapse all the way.

I also ordered the ORD heavy duty front shackles. They are slightly longer and allow the spring to flex and move around a bit more without hitting the frame. http://offroaddesign.com/catalog/hdshackles.htm

Even if you don't off road it a lot it is still a possibility. I damaged my shocks on my old Blazer in road construction on a highway. For miles they kept having BUMP signs and there was nothing. So back up to 65 mph and ignored the next few- until there was a "ramp" before a bridge. Caught some air and hit very hard.


Removing my sway bar made the truck ride much nicer. I can still corner on the highway just fine. Easy way to check... just leave the 2 large bolts that connect it to the axle off. Rotate the sway bar upward and zip tie it out of the way and go for a drive. I liked how it rode so much then I came back and undid the clamps that held it onto the frame and removed it. Removing it also gives you much better articulation in the front for going over uneven surfaces.

 

[Pender1]

http://offroaddesign.com/catalog/bumpstops.htm

I think on my current truck I ordered the 4.5" ones. I think the stock ones were 2" or so and I put a 3" lift on this truck. Basically try to extend the bumpstop down about the same as the lift to keep the springs from compressing too much in case of a huge bump and either breaking the spring or bottoming out the front shocks. The front shocks are so short to begin with when you get longer ones for the lift they can collapse all the way.

I also ordered the ORD heavy duty front shackles. They are slightly longer and allow the spring to flex and move around a bit more without hitting the frame. http://offroaddesign.com/catalog/hdshackles.htm

Even if you don't off road it a lot it is still a possibility. I damaged my shocks on my old Blazer in road construction on a highway. For miles they kept having BUMP signs and there was nothing. So back up to 65 mph and ignored the next few- until there was a "ramp" before a bridge. Caught some air and hit very hard.


Removing my sway bar made the truck ride much nicer. I can still corner on the highway just fine. Easy way to check... just leave the 2 large bolts that connect it to the axle off. Rotate the sway bar upward and zip tie it out of the way and go for a drive. I liked how it rode so much then I came back and undid the clamps that held it onto the frame and removed it. Removing it also gives you much better articulation in the front for going over uneven surfaces.

Thanks for the info. I may go for the shackles, but for $60 I think I can just space my bump stops down.

 

[77 K20]

My bump stops were no longer soft rubber. They turned into like a solid plastic.

 

[bucket]

Would removing the sway bar hurt my drivability? This isn't going to be a DD, but it will see a good amount of around town driving.

Nope, not at all. Even on the Burb my wife used as a DD, it handled the road fine.

As for the bumpstops, that's something I've never messed with, never needed to. Well, I kinda jumped the truck once or twice, but other than that it's never been needed.

 

[firebane]

I know on a IFS front end a swaybar makes a massive difference. I would say because the front end of our trucks are solid axle held together with springs that the sway bar probably doesn't come into play much.

 

[Pender1]

I might just pull the sway bar now and see if I notice a difference. If I need to put it back on I can space it when I get my lift.

One thing I noticed last night, when I lift the truck my front driveshaft looks like it'll be awful close to the exhaust coming out of the passenger side of the engine. Is this going to be an issue?

 

[skysurfer]

If I remember correctly the front drive shaft was either too close for comfort or actually touching so I had the local muffler shop weld in a new crossover pipe that hung down a little lower.

 

[cfieldchevy]

Or just go with headers and dual exhaust right
Thinking about that myself

 

[bucket]

Not sure about the y-pipe myself, I've always run headers and duals.

 

[cfieldchevy]

What size pipes and what mufflers?