Some "Z-ing" Questions unique to my application?

[liljimsrodragz]

whats the minimum Z for a 70 chev Shortwide to get it to lay frame? I am assuming I will have to modify the trans tunnel and....? If so how much? I know its been asked a million times but its nice to be able to have my own thread where I ca ask questions about a response if I dont understand it.

On the sae topic, whats the easiest andmost efficient way? Do I need to brace each frame section so it wont become 'Un-Square" ?

If I section the crossmember will it make more or less problems? Mainly worried about clearance? Advantages to the z and sectioning VS just zing?

[72hotrodder]

i did just the Z. was pretty easy just measure alot so you can keep everything square and level and i welded some rods across the frame on the top and bottom of the frame in front and behind the section i planed to cut. and yea you will need to raise the tranny tunnel also. i raised mine 3in just so i know it would work.

[liljimsrodragz]

Oh ok....One of my biggest questions is where exactly did you slice the frame? Do you have pictures of that area and possibly of your trans tunnel befrore and after modification?

Thanks, James

[RunninLo]

From one of my other posts on the topic

Originally Posted by jrsmith_2010

hey guys, i found a new project that hopefully will be buying sometime this week, its a 69 swb. so ive got some questions

how low did u go on the zing of the frame?
No Z for me. I went with a Dropped x-member

how many inches for the bodydrop?
Still trying to decide if this is necessary. I'll know more once my body is back on. Having done several SFBD's I may go that route. I've heard two schools. one says you can get to the pinch by simply moving the mounts down or shaving the rubber.
did u have to modify the crossmember?
Like I mentioned before I went with an aftermarket x-member replacement. Best choice for me. I've done Z's before but like this route so much better. It addresses many of the concerns that pop up with this type of change. And can be done in an afternoon

how did u modify the tranny mount?
replacement mount was provided with my x-member kit making it an even better solution. If you can handle a Z though modifying or making a replacement trans x-member should be a piece of cake

any help will be great before i start tearing into it

My Z advice: Measure,measure, measure, get your self several sets of jackstands and some shims to get everything level. I usually put four stands under the frame and then I have a piece of 1" thick plywood that I but a screw jack under each corner and then put 4 jack stands on top to hold up the frame clip in front of the cut line for the z. I weld a piece if scrap angle ( old steel bed frames I got for free) across the top and bottom of the frame about 2" on either side of the cut line. and then one diagonal left rail to right on both side of the cut. The bracing keeps the frame sections from spreading,twisting, etc... I prefer a perfectly vertical cut ( some will angle to slide the suspension forward as it goes up). I lay out my cut line and then make two horizontal marks on the frame spaced apart the amount of the Z. I'm picky enough I'll take a punch and trace the lines with dots. marker/paint can get wiped off a good layout mark won't. It's a PITA to realize after the frame is cut that the measurements wiped off.( Did I mention MEASURE) Once you're ready to cut just try to be a clean as possible. Once the cut is complete, I crank up the 4 screw jacks until I've got my desired Z. A few rounds with the level checking front to back and side to side It's time to weld it back in place. The front horns are done similarly although due to their smaller size I forgo the screw jack set-up.


hope this helps liljim, and I'm pretty sure it's 2.5" min to set the main rails flat

Josh

[liljimsrodragz]

Hey thanks for the tips. Where on the frame rails do I make the cut though?

[SCOTI]

Originally Posted by liljimsrodragz

Hey thanks for the tips. Where on the frame rails do I make the cut though?

There is no "one answer fits all" that's correct. The cut will be after the firewall of the cab but before the front suspension..... cut where it works best for you w/o interfering w/the cab. If you're not sure where that is, you're not ready to do a frame 'Z'.

[72hotrodder]

i used a strait edge and cut exactly were my firewall was. but like said theres no (one) spot. just somewere befor and after the crossmember. typicly the area were the frame starts to arc down towards the ground after the shock mount

[liljimsrodragz]

Originally Posted by SCOTI

If you're not sure where that is, you're not ready to do a frame 'Z'.

I realize that I am not ready, why do you think I am asking questions?

[Imperial Kustom]

2-1/4 inches will bring the A-arms above the bottom of the frame rails. However, 2-3/4 to three inches is a good amount of Z. Keeps the lower A-arms from hitting the ground at full dump. As for tha spindles, arms and crossmember, this is the way I do it. There are many more ways, this is just my method. I cut away up to 2-1/2 inches (vertical) from the outside of the crossmember where the spring pocket is and use 3/16" plate to build an upper 'bag mount and use a plate for the lower A-arm. Add 2" drop spindles and the frame sets nicely (and hard!) on the floor. These measurements are for a front end using 27" or taller tires, so adjust the outer crosmember sectioning accordingly for the tire you plan on running.

[63 & 64 Bowties]

Originally Posted by Imperial Kustom

2-1/4 inches will bring the A-arms above the bottom of the frame rails. However, 2-3/4 to three inches is a good amount of Z. Keeps the lower A-arms from hitting the ground at full dump. As for tha spindles, arms and crossmember, this is the way I do it. There are many more ways, this is just my method. I cut away up to 2-1/2 inches (vertical) from the outside of the crossmember where the spring pocket is and use 3/16" plate to build an upper 'bag mount and use a plate for the lower A-arm. Add 2" drop spindles and the frame sets nicely (and hard!) on the floor. These measurements are for a front end using 27" or taller tires, so adjust the outer crosmember sectioning accordingly for the tire you plan on running.

wouldn't happen to have pics, or a build thread would you?

[badblu97]

OK, so I know mine is a different frame, (82) but we did a 3" Z. The cut was made where the frame starts to turn down to go under the firewall,(like someone said earlier) and figure out if you are going to BD the truck or not before you tunnel...just my $.02

oh, and my buddy that did the Z has a sheet of fairly thick steel on the shop floor to weld all of his body mount posts( to keep them in the correct places) mostly for building back-halfs and 3/4 frames, but he said it helped a bunch Z-ing mine!

Dad always said "measure twice, cut once" GOOD LUCK and be patient!

[SCOTI]

Originally Posted by liljimsrodragz

I realize that I am not ready, why do you think I am asking questions?

No disrespect intended.

There are guys out there that ask similar questions that are not ready but don't realize the fact. Then.... they start cutting up their truck only to have a big mess instead of a cool (& safe) ride.