I have both and no, the Z1 will not stand up easily. He would have slid to the back to weight the wheel then using a lot of clutch - brought it up. Back in 1977~78 my roomate had one with Kerker, K&Ns, a 16" tire laced, and had been well set-up by our local Kawasaki performance dealer. I would hammer the bike in 1st and 2nd leaving black marks at will, but never a threat to wheelie.
Now, every stock Z1 I've ridden including my 76 KZ900 will eat a stock CB750. The numbers say it's 81 horses against 67 - weights are about the same. Last summer we dragged my fresh 900 with new valves, bores, rings, and clean-up porting against my 836 and the 900 could not win that battle. I was on the Honda and never ran it above 9,000 rpm. The Z is only fast if you wind it up to redline (9,000), but it would not catch the Honda.
What the Z does better than the Honda is comfort. I give Kawasaki credit for a few things - the CB750 is a bike you "sit on" the Kawasaki is one you "sit in". Don't ask me why, but the Z1's, H1's and H2's all did a great job of giving it's operator a sense of inclusion - you're a part of it. With the Honda, I feel I'm sitting on top of it.
Gordon