Here is an alternative to adjustable lower control arms or strut mounts for a Z car. The goal:
Adjustable camber without disassembly.
OE Automotive components (for safety factor).
Ability to raise the inner control arm pivot:
To bring the roll center and bump camber gain on a lowered car closer to stock.
To reduce OE bump steer (and not vary lower control control arm length which could induce bump steer).
The chosen path was to make the inner control arm pivot (on the front lower crossmember) adjustable using cam bolts. Using camber bolts gives greater range of adjustment than is possible with eccentric control arm bushings.
Because I was also raising the control arm pivots 3/4", I had to remove the control arm pivot reinforcing washers in the cross member. If not raising the pivot, you can slot the existing holes. The below photo of the cross member shows the spot welds on the upper washer (in the picture) drilled out and the washer removed. The lower washer is still present and the three spot welds are visible.
The original inner control arm pivot and spot weld holes were welded up and new holes drilled 3/4" higher. The holes were then slotted about 3/4". Every 0.2" of slot provides about 1/2 degree of camber adjustment. Plan your side to side hole location and slot length based on whether you need to reduce or increase camber. Note that as you reduce camber, the control arm pivot will come closer to hitting the inside of the cross member. You can grind some of the material off the top end of the control arm (as detailed in the JTR manual (http://www.jagsthatrun.com/Pages/Datsun_Z_V-8.html), plus gain clearance by raising the pivot less (or not at all). Mock up what you want to do to check for adequate clearance before drilling & grinding. The below image is a roughing out of the slot (I ended up having to bring it to a machine shop to have it welded up a bit to true the sides, then final machined -- fair warning...).
The key element is an appropriate cam bolt. Ford offers a camber adjusting bolt that is the same thread diameter as the Z (although a more coarse thread), with a suitable length, and best of all large cams that minimize the amount of fabrication required. They are available as Ford #'s F65Z-3B236-BB (cam bolt) and F65Z-3C178-AA (rear cam washer). Two each are required to do the job. You can also get equivalent aftermarket alignment cam bolts by ordering ones for the following applications:
1997 - 2003 Ford F150
1997 - 2002 Ford Expedition or Lincoln Navigator
The cams on these bolts are large enough that they actually ride on the lower / outer flange of the control arm. In the below image, as you rotate the bolt clockwise, the cam push against the flange and moves the bolt inboard in the slot, reducing camber. Note that the machine shop also does sandblasting and powder coating!
You still need something for the cam to push against as you turn the bolt to increase camber. I had the shop weld a small piece of metal onto the face of the cross member for the cam to push against. The location for this can be determined by inserting the cam bolt into the slot, and rotating it back and forth while holding a rod or pencil along the inside of the cam. For my purposes, the metal rod needed to be welded to the cross member near the inside top of the cam. If you are doing this mod without access to a welder, you may be able to drill and tap hole and thread in a short bolt for the cam to push against (make sure the bolt does not interfere with the control arm). In the below picture, the black section of rod is visible near the upper left of the cam.
You need to weld the rod on the back side of the control arm as well, to ensure the cam moves in and out uniformly (the rod is barely visible top right of the cam):
Depending on whether you removed the cross member pivot supporting washers (and how bad you buggered them up in the process), you will need to re-use them or buy new washers the same thickness for reassembly. The OE lower control arm bushing sleeve is not very thick, so if you get new ones, it is better to get ones with a slightly smaller hole and drill them so the just fit over the cam bolts, rather than to buy ones that have too large a hole.
Note that as with any adjustable control arm or pivot, small camber adjustments result in a large change to the toe (you must do an alignment whenever you adjust camber).
Here's to improved handling / reduced tire wear...