theyd be TT500c-e 76-78 tripple trees had straight forks/solid handle bar mounts TT500f gh had leading axle /solid handle bar mounts same as yz125/it175def,
XT 500c-f had straight forks/rubber mounted handle bar clamps and hole/slot in steering stem for steering lock and XT500gh had l/axle forks and rubber mount bars.
tanks and frame tank mounts are different between the straight and leading axle forks also
TT5Matt