You might be right, but we don't yet know what's in the Stage III performance kit.
Here is what Hennessy does to get the Redeye to 1035 HP:
* Note: They use the stock Redeye supercharger.
HPE1000 Hellcat Redeye Upgrade
Available for the 2019 – 2021 Dodge Challenger SRT Hellcat Redeye.
POWER:
• 1035 bhp @ 6,500 rpm
• 948 lb-ft torque @ 4,200 rpm
INCLUDES:
• Lower Pulley Upgrade
• Upper Pulley Upgrade
• Ported Supercharger Snout
• Stainless-Steel Long Tube Headers
• High-Flow Catalytic Converters
• High-Flow Mid Pipes
• High-Flow Fuel Injectors
• High-Flow Air Induction System
• Crank Case Ventilation System
• HPE Calibration Upgrade
• 2 Year /24,000 Mile Limited Warranty
Doesn't seem too far out of reach to me.
I don't really think we'll see 1312 HP at the crank from Dodge, but I do think we will see something very close to 1000 HP.
Source:
1000 HP Dodge Challenger Hellcat Redeye Upgrade | Hennessey Performance