Just thought I'd share my experience with my '78 CB750F in case anyone else is interested in doing the same. I did the 530 conversion, with a 14 tooth front and 39 tooth rear, and a 100 link DID O-ring chain, and I'm super pleased with how it works. I wanted lower cruising RPMs, and the bike'll do 4200rpm even at 75 mph. There is no problem taking off from a stop, and the bike still has plenty of pulling power even if you don't kick it down a gear. If going with this sprocket setup though, you will need a 100 link chain and not the 104 or 105 or more. This being my first bike and my first chain replacement, I didn't realized what a huge difference a new chain could make in terms of riding smoothness and quality!
