Hi Jon,
Jon: "...........the exit points of the two King's Chamber Shafts are located by Petrie at the top of layer 102 and 103 at 3119.1 inches and 3148.4 inches above the pavement. Using Goyon's figures the same shafts would be 3127.2 inches and 3157.1 inches above the pavement which would mean a subtle change in angle......
.....I can't make up my mind whether all this is significant or not"
As regards star alignment theories its not significant.
If different surveys give different exit heights for the shafts, the angles of incline are affected, and this might appear to have significant implications for star alignments.
However, concerning the angle of incline at the top of the upper shafts - these were measured manually - they are not calculated measurements, so the measured 45 deg incline for the top of the upper southern shaft and the 31.2 deg incline at the top of the upper northern shaft remain the same - whatever the heights above base level for the exit heights are, they do not affect these measurements.
This means the top of the south shaft was facing an area of the sky where the distinctive 3-star asterism in the centre of Orion (sAH) crossed every 24 hours c.2570 BC, and the top of the north shaft was facing an area of the sky where the North or Pole Star Thuban crossed every 24 hours when it reached its highest point in the sky due north, also c.2570 BC.
The disparity between Petrie's and Goyon's exit heights does not affect Khufu's ascent to the sky, emerging from his Akhet (the superstructure of his pyramid) heading in his preferred direction - as the 'Dual King' (nswt bit) over the 'Two Lands' (tAwi) he still had all the bases in his celestial realm covered.
CT