Shimano Dura Ace 7400 8 speed w/ 9 speed shifters

Dura Ace 7400 series was released as 6, 7, and 8 speed groupsets.

Indexing is not compatible with non Dura Ace shifters, however a 9 speed shifter can run an 8 speed cassette with 7400 derailleurs.

Speed
8
Shifters
Shimano Sora R3000 Shifters
Shimano Dura Ace 7700 Shifters
Shimano Dura Ace 7700 Bar End Shifters
Shifter variations
Shimano Sora R3000 Shifters ST-R3000-R Right (rear) Clamp
Shimano Sora R3000 Shifters ST-R3000-L Left (front) Clamp
Shimano Sora R3000 Shifters ST-R3030-L Left (front) Clamp
Shimano Dura Ace 7700 Bar End Shifters SL-BS77 Bar end
Shimano Dura Ace 7700 Shifters ST-7700 Right (rear) Clamp
Shimano Dura Ace 7700 Shifters ST-7703 Left (front) Clamp
Rear derailleur
Shimano Dura Ace 7400 Rear Derailleur
Rear derailleur variations
Dura Ace 7400 Rear Derailleur RD-7401
Dura Ace 7400 Rear Derailleur RD-7400
Dura Ace 7400 Rear Derailleur RD-7402
Bookmark
Sheldon Brown Shimano Dura-Ace Compatibility