You can use this tyre size calculator to check what fits:
https://www.inawise.com/tyre-calculator/tyre-size-calculator.html
In a discussion with a Policeman, he wasn't worried about the speed rating, but was worried about the breach of the ADRs for diameter.
My insurer (Allianz) weren't worried about the diameter, they were worried about the breach of the ADRs for width, because of the increased risk of aquaplaning ...
Doesn't matter which way you jump, once you get away from standard sizes as allowed by the ADRs in any dimension, someone doesn't like it.
I even considered going back to 15" rims, but the price starts to climb, for little to no advantage off-road, and the ever-present risk of interfering with the all-important on road safety and handling.
With a 1968 Landcruiser, one chooses tyres for purpose, and this has little effect on the general handling and stability of the vehicle. With our vehicles, their (excellent) handling is a result of all the parts, including tyre size, being in perfect balance. Interfere with any one aspect and this balance will be changed.