Not only is that shock WAY too long (You're looking for around 320mm in total legnth, the '97 750 is another 25mm/inch longer than that), but it's sprung for someone 130lbs and lighter.
The BEST shock to use is the Suzuki GSXR 1000 from 2005~07, 319mm long 475in# spring. That'd be good for riders in the 180~220lb range (most of us I suspect.. actually, I'm the next range up).
320mm is about the magic legnth, and 450in/lb spring would be right for someone 130~180lbs, 475in/lb for someone 180~220, and 500in/lb for 220+ riders (I'm 260 and 500 was perfect for street riding, Very forgiving... would be considered a "rain" setup for most track riders, though I like softer settings).
I wouldn't go any longer than 320mm... negative returns after that. And adjusting the dogbones to compensate for the legnth will alter the spring rate/valving needed... so do that at your own risk (unless you posess the math to calculate the percent change, and adjust accoridingly).