Ignore ED mate, he seems to have a problem reading between the lines and adds the occasional dumb ass comment.
There's no real fast way to do the wheel swap unless you use the forks off the ZX too, that way you won't have to adapt the brakes to fit and make wheel spacers or ,maybe, if needed, change bearings. You can find all this info out by checking axle sizes and measuring disc spacing, there's a few guys here that should be able to help. I have a friend thats put ZX wheels on an 82 GPZ but that won't really help you, there's more differences with the earlier bikes. Same goes for the rear, check axle sizes and measure or ask for hub width, you'll probably have to alter spacers to centre the rear wheel, you'll also have to measure the rear sprocket offset to make sure you're chain is aligned and sort out the rear brakes, there's more to it than it looks....
Hope that was more helpful...
PS, you also have your speedo drive to take into consideration, I think the ZX wheels are 18 inch at the front, your 78 would be 19 inch...