Checking CR calculation for homebrew larger version of Giant Ape

I am considering allowing a larger version of a Giant Ape, in which some of the stats have been embiggened to achieve the low end of CR8.

I would appreciate a confirmation that I am calculating this correctly.

In particular, it appears that what the DMG calls Damage Per Round, what is actually being assessed is average damage per round, assuming that the maximum number of most damaging attacks hit.

CR7 Giant Ape
AC12, 157hp (15d12+60), At. 2 @ +9 to hit, 3d10+6 dmg, DPR 45

CR8 Proposed Giant Ape [all other stats as RAW Giant Ape]
AC13, 168hp (16d12+64), At. 2 @ +9 to hit, 3d12+6 dmg, DPR 51

CR7 Giant Ape Calculation
Hp 146-160 = CR6, AC is more than two below 15, adjust DCR -1 to 5
DPR 45-50 = CR7, to hit is more than two above +6, adjust OCR +1 to 8
Average CR 6.5, round to CR7

CR8 Proposed Giant Ape Calculation
Hp 161-175 = CR7, AC is two below 15, adjust DCR -1 to 6
DPR 51-56 = CR8, to hit is more than two above +6, adjust OCR +1 to 9
Average CR 7.5, round to CR8