+1 on the frame kit. I just put mine in this last week. It was not difficult and was more of an experiment since, if it worked as well as claimed, I was going to use it in all of my vintage bike builds...or some version of it.
I left the engine in the frame while I worked on it. After I put it in I timed myself on the removal of my engine (carbs and all ancillary equipment removed). From start to finish...removing the engine took me less than 5 minutes. Because I'm SUPER anal I put the engine back in...<4 minutes. Then I wiped the bottom of the engine down with baby powder and removed the engine again. Once again less than 5 minutes but this time I had proof that the engine did not touch the frame anywhere. This was all done with a floor jack under the engine and a motorcycle lift next to it.
i also pulled the head off the engine with it in the frame. Just take a moment to imagine how much nicer it would be to work on your engine if you didn't have to worry about messing up a beautifully coated frame by banging your engine against it when, undoubtedly in the future you want to hot rod that motor...
Long story short...i'm designing a similar kit for a Kaw H2 Triple, a GL1000(more for carb removal), a KZ1100, and a KZ1000.