Yeah,they are. I've seen a ZR7 frame stripped down and I am pretty certain that the whole lot is a zephyr frame with the rear redone for a monoshock,the cradle looks identical. Which unfortunately means the 11 engine won't fit,its just too big for the 750 frame. However,I'm pretty confident that the old GPZ1100 engine (the aircooled from the early 80's) can be persuaded into place,I'm going to be seeing Mustapha over the christmas period (not that he knows yet.......lol) to borrow a set of cases in order to check it all out,so keep 'em peeled....:rock: