Hi
welcome to the forum and i'm gonna take an educated guess you might be in Australia

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As far as I am aware all the bonnets are the same length for 4 cyl tractors. anything that has been converted to 6 cyl will be somewhere close to a foot longer, depending on how long the guy made the frame rails, and hood to fit during the conversion

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for a super the only difference will be the shape of the bonnet locking handles compared to new major and power majors, and also the holes that the model type badges bolt to/ blue orange super had cast badges along between the curve and the bit that steps out with handles on, so had a line of 3 or 4 holes there.
The last blue grey super had no badge mounting holes just stick on badges. The power and other majors had holes down the back bottom sides, in the part the handles are fixed on. I guess you are needing a bonnet to be asking

, some older bonnets didn't have the oval flanged hole in for the air cleaner top to come through either

, so if looking you need that hole also for supers and power majors . I have swapped damaged bonnets and just welded badge holes with a mig and lightly body filled the grind marks, then re drilled holes somewhere else if needed, if the bonnet wasn't right for my badges/ tractor type.

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Hope this might help you,
Regards Robert