Should I "Z" the front? Opinions please.

[Popcorn W]

Long time lurker who finally joined. I've been following lots of builds here. There doesn't seem to be a huge number of Z-ed trucks or maybe I'm missing them.
I'd like opinions from the experts I see on here please.
I don't mind fab work at all, and to me it looks like a 2"-2.5" Z is an easy way to get that extra 2+ inches. I know the steering has to be reworked, but there'd be no need to pancaking the crossmember, right?
I'm looking to get somewhere close to laying frame.
Just got my step notch kit in the mail for the rear, but I'm undecided on the front. Going to do the rear notch then start up front with cupping the LCA's.
Here's a pic to see where I'm at so far. I basically have a "blank canvas" to work with now.
Thanks

[PGSigns]

With air and drop spindles and a tire about the size of yours mine will drop the front till the cross member just misses landing on the ground. The back with the rear end resting on the bottom of the bed is the limiting factor of it going any lower aired out. You may want to pop the springs out of it and set it down and see where it lands. That will give you an idea of how far you need to go. Got the cut the bump stops off the lower control arms to let the front down.
Jimmy

[chevyrestoguy]

Are you looking to Z the chassis for the benefit of maximum drop or just to gain extra ground clearance at ride height?

We Z'd my '64 2 inches, and while it was apart, moved the section 1" forward to center the front wheels in the fender openings. Z'ing the chassis is a cheap way to gain ground clearance, which is a critical commodity on our trucks when they get lowered. If you lower the truck more than 5" in the front, the lower control arm clearance to the ground becomes a major concern, and over time, you'll beat them up. There are threads on the site showing how guys made their cuts, and the common way is to make your rear cuts at an angle, so when you raise the crossmember up, you're bringing the wheelbase forward at the same time. The actual cutting and boxing is relatively simple, and the cost is basically whatever the material is for the boxing plates at the frame splices. To make things as simple as possible, just ensure that your cuts are made behind the core support and aft of the upper shock mounts. You MUST keep your core support in the stock location, and you need to ensure that the shock points move up together with the Z. You want the steering box, crossmember, and shock points to ALL move up together as one unit. The harder work (more tedious) comes with everything that is affected by the Z, like the steering column linkage, brake lines, trimming the inner fenders, re-drilling the position of the drag link, and motor and trans mounts. For the column linkage, you will need to cut your shaft and add a u-joint, and if you go 2" or higher on the Z, you will need to clearance the driver's side upper control arm because the shaft will hit at full compression of the suspension. Brake lines can be either be spliced or completely redone (recommended). The inner fenders will need to have the lower edges trimmed because the framerails will now be higher. The drag link mount of the passenger side will need to be repositioned, which is a simple drilling of a new hole in the bracket. The motor and trans mounts are up to the option of the installer. You can leave the engine mounts in the original location on the crossmember, but you'll have to trim the transmission cover in the floor if you have a low hump. If you have a high hump floor, you'll be OK. The trans mount will have to be shimmed or you'll have to make a new mount to keep the engine/trans at the right angle. Also, keep in mind that you should always recheck the entire driveline angle from the transmission all the way back to the rear end after any major mod like this. Oftentimes, you will have to shim or reposition the carrier bearing to keep the driveline angles correct.

If you like to fabricate, and you want to do stuff for less cash, Z'ing is a great way to go. Just be prepared to do a lot of the little details to make it all work properly.

[Popcorn W]

Originally Posted by PGSigns

With air and drop spindles and a tire about the size of yours mine will drop the front till the cross member just misses landing on the ground. The back with the rear end resting on the bottom of the bed is the limiting factor of it going any lower aired out. You may want to pop the springs out of it and set it down and see where it lands. That will give you an idea of how far you need to go. Got the cut the bump stops off the lower control arms to let the front down.
Jimmy

Thanks Jimmy. I was wanting to keep these stock tires and wheels and add poverty caps. They're about 27.5" so it sounds like I'd be happy with your route. Did you cup your LCA's? I don't completely understand the big gain on cupping since there's a pretty good factory cup now. Maybe I'm missing something but it looks like I'd only gain 1/2" or so? I like your idea of popping the springs and seeing what happens with the tires on the ground. I haven't cut the bump stops off yet, I was waiting until I removed the LCA to do that. I'll cut them off now though and see how it looks. That was a big help.Which drop spindles are you using? 3"? And, of course on the rear, the bed floor's gotta go. Thanks

Originally Posted by chevyrestoguy

Are you looking to Z the chassis for the benefit of maximum drop or just to gain extra ground clearance at ride height?

We Z'd my '64 2 inches, and while it was apart, moved the section 1" forward to center the front wheels in the fender openings. Z'ing the chassis is a cheap way to gain ground clearance, which is a critical commodity on our trucks when they get lowered. If you lower the truck more than 5" in the front, the lower control arm clearance to the ground becomes a major concern, and over time, you'll beat them up. There are threads on the site showing how guys made their cuts, and the common way is to make your rear cuts at an angle, so when you raise the crossmember up, you're bringing the wheelbase forward at the same time. The actual cutting and boxing is relatively simple, and the cost is basically whatever the material is for the boxing plates at the frame splices. To make things as simple as possible, just ensure that your cuts are made behind the core support and aft of the upper shock mounts. You MUST keep your core support in the stock location, and you need to ensure that the shock points move up together with the Z. You want the steering box, crossmember, and shock points to ALL move up together as one unit. The harder work (more tedious) comes with everything that is affected by the Z, like the steering column linkage, brake lines, trimming the inner fenders, re-drilling the position of the drag link, and motor and trans mounts. For the column linkage, you will need to cut your shaft and add a u-joint, and if you go 2" or higher on the Z, you will need to clearance the driver's side upper control arm because the shaft will hit at full compression of the suspension. Brake lines can be either be spliced or completely redone (recommended). The inner fenders will need to have the lower edges trimmed because the framerails will now be higher. The drag link mount of the passenger side will need to be repositioned, which is a simple drilling of a new hole in the bracket. The motor and trans mounts are up to the option of the installer. You can leave the engine mounts in the original location on the crossmember, but you'll have to trim the transmission cover in the floor if you have a low hump. If you have a high hump floor, you'll be OK. The trans mount will have to be shimmed or you'll have to make a new mount to keep the engine/trans at the right angle. Also, keep in mind that you should always recheck the entire driveline angle from the transmission all the way back to the rear end after any major mod like this. Oftentimes, you will have to shim or reposition the carrier bearing to keep the driveline angles correct.

If you like to fabricate, and you want to do stuff for less cash, Z'ing is a great way to go. Just be prepared to do a lot of the little details to make it all work properly.

As for the question as to why....I guess a combination of both really. I had read here where more than 2" creates more problems just like you confirmed. You sure gave me a lot to think about with all the little stuff I didn't know about. I thought it would be a simple as only heim joints/universal joints on the steering shaft, brake lines of course and good to go. From what I've read here, trim the bottom of the driveshaft tunnel on the rear crossmember and with the Z, and spindles it should sit on the frame? Thanks for the detailed description! I knew I came to the right place.
And yea, I actually do enjoy the fabricating part.

Thanks guys!

[tinydb84]

I Z'd 75 but am not completely back together. It was a fair amount of work but it was pretty fun doing it.

My 66 has a sectioned crossmember (2''). Honestly it looks like just as much work (I didn't do it). The motor was moved up and forward, the steering was raised, the steering shaft had a heim joint added. I prefer a Z because it buys you more drop with a similar amount of work.

FYI on my 66 they lowered the body mounts an inch to get an inch more drop. Might be an option for you if you want.

[bagged74]

Its not a 60-66, but I Z'ed my blazer 2.5" and cupped the lower arms. Its definitely a cost effective way to get your truck low if its done correctly. measure,measure,measure.......

[tinydb84]

Damn. Nice blazer.

[bagged74]

Originally Posted by tinydb84

Damn. Nice blazer.

thanks!

[Popcorn W]

Nice Blazer!
Did you use the stock upper control arms? I'm just wondering about camber.
I assume with the longer tubular uppers you can't z because of the steering shaft.

[bagged74]

Originally Posted by Popcorn W

Nice Blazer!
Did you use the stock upper control arms? I'm just wondering about camber.
I assume with the longer tubular uppers you can't z because of the steering shaft.

I narrowed my lower arms 1" instead of using longer uppers. My uppers are stock.

[tinydb84]

Originally Posted by Popcorn W

Nice Blazer!
Did you use the stock upper control arms? I'm just wondering about camber.
I assume with the longer tubular uppers you can't z because of the steering shaft.

You have to reroute your steering over the control arm either way.

Originally Posted by bagged74

I narrowed my lower arms 1" instead of using longer uppers. My uppers are stock.

I did 7/8" and it ended up being a hair too much and I had to shorten my uppers a bit to get rid of my positive camber.

[bagged74]

Originally Posted by tinydb84

You have to reroute your steering over the control arm either way.



I did 7/8" and it ended up being a hair too much and I had to shorten my uppers a bit to get rid of my positive camber.

I did an inch because I plan on narrowing my uppers about 1/2"