IH 1066.
126 PTO HP.
For new production, true Hydros cap out in the mid 60s, then it becomes a question of if CVT is close enough in function to count. If it is, I think somewhere around 600-700 HP is the limit.
JD 4066s 66 engine HP and 54 PTO HP in both R and M. Both models weigh 3770lbs with ROPS. R Cab weighs 4675lbs.
Massey 1760M 60 engine HP-44.4 PTO HP. 3968lbs ROPS and 4464lbs Cab.
Kioti NX6010-60 engine HP and 48.3 PTO HP. 4211lbs ROPS 4548lbs Cab.
Mahindra-Their product line is impossible to decipher for me. Pass.
LS-same as Mahindra. Pass
Kubota
L6060-60 net engine HP-53 PTO HP. 3990lbs ROPS, 4365lbs Cab
Massey is very PTO inefficient. 74%. Everyone else is in the 80s, with Kubota handily winning, being 85.5% or 88.3% efficient, depending on if you look at gross or net engine HP. No other manufacturer lists net vs. gross engine ratings that are easily found, so I'm unsure which they advertise.
Kubota and JD are the clear front runners. Though I do want to know where all that weight, 905lbs of it, comes from when you jump to the 4066R cab. Clearly a bit of an outlier.