Z-bar too narrow?

You can shim the frame-side in/out to locate the other end such that it clears the headers BUT, the down rod more or less has to remain in the center of the firewall cutout. To make that happen, you can bend the lever as required but if you do, you have to double-bend it to offset it, so that the downrod stays on the pin.(*1 )
You can move the inboard floating-end ball in out by shimming it at the BH.
The Z-bar tube after installation, should be at 90* to the vehicle centerline in plan view, and parallel to the ground in end-view.
The lever that pushes the fork-rod, should be adjusted to push straight back, so it stays on the pin. If you bend it you will have to again double-bend it in an offset, so the adjuster-rod stays on the pin.(*1)

The TO fork should be about centered vertically in the BH window, and towards the engine side of the window in the horizontal, but leaving just enough room for the rubber bellows/boot. When you push the clutch-pedal down, the TO fork should move smoothly to the rear of the car, and your clutch departure should be about .080 with a 3-finger clutch; can be down to half that with a diaphragm, so long as the gears in the trans actually stop spinning in a reasonable period of time, and there is no grinding or creep. You should NOT have to push the pedal to the floor. If you do, then you have the wrong pedal-ratio. Half to three-quarters should be enough.
There is provision on the TO fork, to install an anti-rattle spring on it, to pull it towards the engine. There is a corresponding cut-out, close to the starter, on the BH face that bolts to the block. This is to pull the TO bearing OFF the PP. Not all models got the spring but the provision is there so I use it.

With TTIs yur gonna find out that adjusting the Freeplay is a royal PITA. To mitigate this, instead of having the semi-locking adjuster nut on the engine side of the TO fork, I put a standard nut there, that is easy to turn with just my fingers. Then I install the half-ball swivel, then a spacer , then a lock nut last. The spacer needs to push the lock-nut out for access by a deep socket.
Now, to set your freeplay, all I do is crack the lock nut, and unwind it a couple of turns, then twist the adjuster nut, and lock it up tight again; it takes longer to put the car up on the curb than to do the adjustment and it can be done with HOT headers, but you gotta use a rag or a glove to protect your knuckles.. To prevent the loss of the lock nut and subsequent loss of freeplay, I drill the Pushrod and install a hairpin or a cotterpin.
Now, here's why I do this, I mean besides that it makes it a whole lot easier to adjust the freeplay;
the factory freeplay is rather generous, and it is made that way so you can go about a year before the pedal comes up, because the freeplay is disappearing. With the ease of adjustment now, I run the freeplay much much less than the factory spec. This has two benefits; 1) the declutching is almost instant, and 2) the pedal travel to get the required departure, is much much less.
The Con is that you gotta stay aware of the minimum freeplay so you don't wear out your TO bearing when it starts spinning along with the PP. I get about 5000 miles out of an adjustment. Since my car is no longer a DD, that translates to once a year.........


Note-1
When I say stays on the pin, I mean that the two pieces in motion, slide by each other in the same plain. Obviously, the way those pieces are made, they will stay on the pin. But if they are not sliding past eachother properly, they will tend to spit the retaining-clip off, and once the clip is gone, then it can happen, and if it does so in traffic, that sucks so much.....

Note-2
The engine often has to be raised or moved over to one side, for best fit of the TTIs. Of course, wherever the engine goes, the BH goes with it. And so fitting the Z-bar is always a challenge. Because the 67 to 72 engine mounts are biscuits,they are not all that strong and you should be thinking of installing a Torque strap. The strap will help keep the Z-bar moving in a constant plain, so that every clutch-event is more or less the same as the last. To help keep the engine in place in the fore and aft direction, I installed a spool mount rear crossmember.