UPDATE: Finally I got the time and a dry day to get back to this. JAMCAR I don't know if one is better than the other. I was fortunate enough to get a Malibu with factory manual transmission so that is what I used. I would hope the reproduction would be better made but I would not count on it. My Clutch and Flywheel Handbook assumes that the factory stuff is weak and advises to strengthen it. Anyway I got the Z-bar out after loosening the entire inner fender. Don't even try it without doing that. Once out I measured the holes in the bar and found they were two different sizes. The larger was a hair smaller than 3/8" (metric?) so I planned on using 3/8" grade 8 bolts. I drilled out both the pushrod hole and the GAGE hole to 3/8". I found a steel bar exactly the right thickness, length, and width I needed and I drilled two 3/8" holes to mount the bar to the Z-bar. Then I drilled three 5/16" holes for the clutch push rod. I did three so I had a selection to test the clutch pedal travel. I scrounged some grade 8 bolts the length I needed and bolted the extension to the Z-bar using lots of Locktite.
Now, to get the Z-bar back into position with the longer extension was pretty easy because I had loosened the inner fender. But I had to really pry it back out of the way to get access to the frame area. I slipped the Z-bar back into place on the block stud and re-bolted the bracket to the frame. Once all was hooked up I realized that the longer bar now hit the canister for the heat riser valve. I could not get the same retraction travel that I had before. This is where it is great to have the SpeedDirect adjustable linkage. I merely adjusted out the top rod to make up for the now shorter lower rod. How neat is that?
OK now to see what I have under there. I adjusted the lower rod with the stud in the closest hole to stock. No good, not enough travel. Next hole was better, but to keep the pedal free play the pedal was still too close to the firewall for my liking. The third and farthest hole from stock was the best. I have plenty of free play and the clutch is totally disengaged way before the pedal gets anywhere near the firewall. That is exactly what I wanted. The change in ratio at the lower Z-bar arm gave me all the travel I needed so I could have both things. The change in pedal effort was not really that noticeable but I will evaluate that after a drive. I also had just enough time to change out my speedometer driven gear while the car was up in the air. I had mistakenly counted seven teeth on my drive gear when I fixed the trans last winter. Turns out it had eight teeth and I miscalculated the needed driven gear. Ooops. Anyway now it is done. I got this finished right before another deluge from the 2019 Monsoon season. I need to take the car to one of those roadside radar set-ups that tells you how fast you are going. It is far enough away that I will be able to evaluate the pedal effort properly- in traffic. Another thing I need to do is to move the lower rod from the side it is on to the other side so it is a straighter shot. It is within the range of mis-alignment for the spherical ball end but I would like it straighter. It is also too clost to that part of the bell housing where the starter mounts. Working under there is tiresome so I left it for now. Plus it is raining so hard right now I expect to see Noah floating down my street.