On The Dyno: GM Iron LSX 427
Tested at Westech Performance Group SuperFlow 901 engine dyno STP correction factor
| RPM | Torque | Horsepower |
| 3,000 | 469 | 268 |
| 3,200 | 470 | 286 |
| 3,400 | 478 | 310 |
| 3,600 | 489 | 335 |
| 3,800 | 498 | 361 |
| 4,000 | 508 | 387 |
| 4,200 | 517 | 413 |
| 4,400 | 526 | 440 |
| 4,600 | 534 | 467 |
| 4,800 | 547 | 499 |
| 5,000 | 552 | 526 |
| 5,200 | 552 | 546 |
| 5,400 | 549 | 564 |
| 5,600 | 539 | 575 |
| 5,800 | 530 | 585 |
| 6,000 | 516 | 589 |
| 6,200 | 503 | 593 |
| 6,400 | 488 | 594 |
| 6,600 | 469 | 590 |
| Key specifications: GM iron LSX 427 |
| Displacement | 427 CID |
| Block | GMPP LSX 19166454 |
| Bore | 4.125 inches |
| Stroke | 4.000 inches |
| Crank | Production LS7 forged steel |
| Rods | Production LS7 titanium |
| Pistons | Mahle forged aluminum |
| Compression ratio | 11:1 |
| Cam type | Hydraulic roller tappet |
| Duration at 0.050 inch | 211/230 degrees |
| Valve lift | 0.591 inch |
| Rocker ratio | 1.8:1 |
| Cylinder head | Production LS7production CNC-porting |
| Valve interior/exhaust | 2.20 titanium/1.61 sodium-filled hollow-stem steel |
| Intake manifold | GM LS7 single-plane four-barrel |
| Test carburetor | Holley 950 HP downleg booster |