How much z

[canadian 4x4]

I'm wanting to sfbd my 83 c10. I have the truck laying crossmember in the shop right now and with welding a piece of 2x4 to the top inside of the frame, my measurements are showing in going to need to z 4".every where I have read people are doing 3" z. Am I doing something wrong or is it going to change that much when I do my cut.

[sduckworth13]

I've heard 2 inches max if your z'ing the frame. I'm just shooting from the hip, I'll look up the thread where I read that and post it for you.

[sduckworth13]

This is chevyrestoguy's build thread, he detailed z'ing the frame.
http://67-72chevytrucks.com/vboard/s...d.php?t=446527

[tinydb84]

I measured mine out though it is a C20. I need 2'' to lay flat and 4'' to do the sfdb with 2x4. Luifer and has two half tons and did 3'' (check his build thread on here). I would go with my own measurements on my own frame.

[canadian 4x4]

i read through luifer's thread, and it worked for him. but i got the same measurements as you tiny.

[tinydb84]

http://www.loweredd.com/Frame_Z.html

He did 4 but cut 2.5 off the bottom. I personally am doing 4''

[canadian 4x4]

i cut it today, 3 will work. your c20 frame is the same height as a c10. i couldnt bring myself to do 4 that was way to much.

[tinydb84]

So where are our 4 inch measurements coming from?? lol

[canadian 4x4]

i have no clue, i had my springs out and crossmember on the ground. and measured from the bottom of the piece of 2x4 to the ground was 4". if it didnt lay out at 3" i wasnt cutting the bottom of the frame off but it did.

[tinydb84]

Steel 2x4 or wood? Just cause a wood 2x4 isn't actually 2''x4''

[canadian 4x4]

steel, yea 3.5" still wouldnt make up for my messed up math

[broey]

I think 4 inches was the amount people did that wanted to lay rocker

3 inches is the normal z

If you plan of doing a z, Id like to offer a better plan of attack:

2 inch crossmember pancake,
1inch Z (straight up and down)
Porterbuilt narrowed and forward control arms

doing this instead of a full z will be so much better. you will keep your engine way lower in your engine bay, your driveshaft will clear your cab much better, and you will have less camber/bumpsteer.

this is just what I would have done if I wasnt running dropmembers.

[tinydb84]

Originally Posted by broey

I think 4 inches was the amount people did that wanted to lay rocker

3 inches is the normal z

If you plan of doing a z, Id like to offer a better plan of attack:

2 inch crossmember pancake,
1inch Z (straight up and down)
Porterbuilt narrowed and forward control arms

doing this instead of a full z will be so much better. you will keep your engine way lower in your engine bay, your driveshaft will clear your cab much better, and you will have less camber/bumpsteer.

this is just what I would have done if I wasnt running dropmembers.

Isn't the 2x4 on the frame to lay rocker? I don't think you can do the 2 inch section of the cross member without significant steering mods. Do mean 2 inch Z and 1 inch section?

[broey]

Originally Posted by tinydb84

Isn't the 2x4 on the frame to lay rocker? I don't think you can do the 2 inch section of the cross member without significant steering mods. Do mean 2 inch Z and 1 inch section?

The 2x4 is to box the frame where the bottom is cut off to lay rocker. When you cut the bottom of the frame off you are now making the front crossmember having to come up 1 more inch so that the frame is again the lowest part of the truck. A 2 inch pancake is the normal amount people do. It also seems to be the most you can do an keep the steering box on place and working properly. So you get the last one inch by z'ing the frame.

[tinydb84]

http://www.captkaoscustoms.com/chopcross.html

I am pretty sure you cant do 2 inches. I started sectioning one after spending a ton of time reading on here. I started cutting mine for 1.25 inches after seeing a bunch of steering issues. I never finished it and am going to do a Z instead.

Edit*

I have see your build tread (nice trucks btw) but I meant the most you can section while maintain factory steering.

[lolife99]

I think you two need to compare apples to apples.
1.25"-1.5" sectioned crossmember with the steering box in the stock location on the frame should work fine.
I think there have been some 2" "pancaked"/sectioned crossmembers,... but the steering box is also raised 2" and the frame is notched for tie rod clearance.
(like Dino has been doing lately)

[tinydb84]

^^^agreed. My 66 is raised 2 inches but the frame is notched and the steering box was moved up 2 inches as well.

[broey]

Originally Posted by tinydb84

^^^agreed. My 66 is raised 2 inches but the frame is notched and the steering box was moved up 2 inches as well.

Yeah I was basing this off of Dino's trucks. Those are the only way I had seen it done. You could do 1.5 pancake and 1.5 z to maybe help. All I'm really getting at is to try to do the smallest z possible.

[chevyrestoguy]

Originally Posted by broey

Yeah I was basing this off of Dino's trucks. Those are the only way I had seen it done. You could do 1.5 pancake and 1.5 z to maybe help. All I'm really getting at is to try to do the smallest z possible.

I agree, Broey. When you start going over 2" on a Z, you open up a can of worms that gets even more complicated the higher you go. I went with a 2", and the job was pretty simple. The part(s) that required the most work was everything else that tied to the frame, like the inner fenders, the engine mounts, steering linkage, and such.