Just checked the FIA record list on their web site. Looks like Mormon Missile runs in Cat A, Group III, Class 10. They broke their own records.
Only faster diesel is the JCB liner that ran in A/III/11 at 350.452 in kilo and 350.092 in mile.
Translation -
Cat A = unlimited ( e.g. Streamliner ),
Group III = blown diesel,
Class 10 = displacement over 5000cc up to 8000cc, . . . . and class 11 is over 8000cc.