Be sure to buy the best new rubber that you can for that, you don't want to join the ranks of guys who get an old bike going again, then throw it away in a turn when the hard tires with "great tread" lose grip. It is a little harder to find good tires for these old bikes, but there are good options.
I love the look of the original Ninja 750, except for the tiny front/huge back wheels. I had an '87 that I bought in '89, it was a great machine, but I dumped it in a turn because I didn't bite the bullet and get new rubber when the rear tire got squared off from too much straight line riding. You do NOT want to depend on the traction of the squared-off edge of an old OEM tire! Broke my collar bone, trashed the poor Ninja. I was wearing what was considered "all the gear" for back then, and let me encourage you to get good gear. True motorcycle jacket with padding, vents, etc., full face helmet, sturdy gloves, boots laced up above your ankles. I wear riding pants, now, too, because the older I get, the less my chances of recovering quickly from hitting hips or knees on pavement, though jeans did me well enough for my little crash back then.
I watch a lot of motorcycle crash compilations on YouTube, and I'm always amazed at the people who end up shoeless and helmetless after a get-off (and the compilations are of the people who survived, I'd hate to see the ones who didn't.) Tie your shoes, people! Buckle that helmet! I mean, seriously?
Scott in Brighton NY