And khufu using mortar to repair the exterior of the whole pyramid is not really an impossible act according to me.What objective proofs exist that it was only the muslim raiders who robbed or removed all the missing casing stones?Even if the pyramids are dated one year before the suspected reign period of Khufu it still could not have been built by him.
Other glaring inconsistencies in your suggested line of builders for the great pyramid is that why are there no ascending chambers passages etc in the so called Khafre pyramid?.Had the custom of building pyramid chambers changed so dramatically.Also why wouldn't khafre built his pyramid bigger then the one built by khufu since he had the advantage of being the second builder.How about radiocarbondating the second pyramid as well to give clues about the timeline of when it was built as this could solve a lot of mysteries surrounding who built/repaired/intruded them and at what time.
I recommend taking careful note of the document Swede linked to in Post 28. I should have posted this link myself, and I should have mentioned the wide-ranging nature of the carbon testing. Khufu's pyramid was only one of numerous Old Kingdom and Middle Kingdom monuments in the test. Errors of omission on my part. What's interesting is that across the board, the dating of these monuments based on their carbon samples reflects how accurate conventional relative dating has been all along.
The fact that Khufu's pyramid possesses an ascending passage is hardly a reason to suggest the pyramid wasn't built by Khufu. How familiar are you with the three pyramids built by Sneferu, prior to Khufu? I recommend spending some time researching them. They, too, possess unusual features, especially the Bent Pyramid. You will also find in the Red Pyramid numerous architectural features which Khufu would incorporate and expand on in the building of his own pyramid, including the corbeled vault. It's true that Khufu's pyramid possesses some unique features, but so do numerous other pyramids before and after his. Without a command in familiarity with all of these pyramids, you're trying to view the Great Pyramid as though it exists in an architectural and cultural vacuum. It certainly doesn't.
As for Khafre's pyramid, he didn't need to strive too hard to make it bigger than Khufu's monument. Khafre was savvy in selecting a spot in Giza that was already at higher elevation than the rest of the Plateau, so he allowed geography to do some of the work for him.
You should also delve into the workmen's graffiti inside the relieving chambers of the Great Pyramid. I am quite aware that oddballs like Zecharia Sitchin and Graham Hancock have tried to interpret this graffiti as a hoax, but their arguments in this direction are comically inept. There's a reason people don't take fringe authors seriously—and why in many book stores the books of fringe authors are located in some other section than the one for history (I've seen them located on the shelves in the New Age and occult sections, for example). The point is, anyone properly acquainted with the orthography and linguistic nature of this graffiti knows it to be unquestionably authentic. It could not have been a hoax. And the graffiti alone solidly ties the Great Pyramid to Khufu.