Don't upset someone who's L Series has recently chewed its valves!
If you use the much maligned but very useful LZ facility called "Search" and enter the tyre size (as it would normally be written) - guess what - you'll get an answer!
You dont need mods for the 235-55-17. I have the Michellin Synergy tires on now. im trying to find a 5th for the spare, but have not found any at the tire shops yet. GOod Luck.