FWIW, when Greg Norman did an interview on that golf talk central or whatever that show was that Peter Kessler used to do, they got on the topic of modern driving technology and ball technology and Greg Norman said the following paraphrased:
"People have no idea how good of a driver Nicklaus was, and how believably powerful he was. If Nicklaus in his early prime had the technology that we do, he would have hit every drive more than 360 yards with more accuracy than he did in his days of playing."
At first I thought Greg Norman was of course engaging in hyperbole, but I'm really not sure anymore. Also, I once heard Arnold talking about how he would be playing with Jack and keeping up with him off the tee (and Arnold was really long for his day and prided himself on his driving distance) and then Jack would just empty the clip after Arnie hit one of his best drives and carry it by like 30 yeards....said it was really demoralizing.