The 7th Cav was a grunt unit (Airmobile Infantry, a fancy name for helicopter transported infantrymen). There were many Cavalry outfits in the Vietnam War: (Not full Regiments; the only full regiment was the 11th ACR), just to name a few:
1. 1st Cavalry Regiment
2. 4th Cavalry Regiment
3. 5th Cavalry Regiment
4. 8th Cavalry Regiment
5. 9th Cavalry Regiment
6. 10th Cavalry Regiment
7. 11th Armored Cavalry Regiment (11th ACR)
8. 12th Cavalry Regiment
9. 17th Cavalry Regiment