member name "fishhead". He makes brake kits & is a wealth of info on the swap! I did a 77gl onto my 75/750. Pretty easy, bearings are the same on cb 70-77 to gl 75-77 after then the bottom gl bearing is different but will still work. I think you need both kits then? Not sure about the 78 cb stem/ bearings though? A cb fender is narrower then the gl one. I used dohc,(78/79?) front, flipped backwards & cropped w/spacers. I put progressive fork springs in, & have had the tubes cheated up, but have found I like it w/ them almost level in the clamps. If you want a gl fender I have one, needs some cleaning. But they are big ass fenders.
jim