Dual-Pattern

Group #1  
PN 12-408-8
Grind XR258HR-10
Intake valve lift 0.480 inch
Exhaust valve lift 0.487 inch
Intake duration at 0.050-inch lift 206 degrees
Exhaust duration at 0.050-inch lift 212 degrees
LSA 110
Intake valve opening 23
Intake valve closing 55
Exhaust valve opening 66
Exhaust valve closing 18
Cranking compression 220 psi
Idle vacuum at 900 rpm 17 inches
Peak torque 483
Peak horsepower 416
Average torque at 2,500-5,500 rpm 456
Average horspower at 2,500-5,500 rpm 345
RPM TQ HP
2,500 440 209
3,000 457 261
3,500 480 320
3,800 483 350
4,000 482 367
4,500 471 404
5,000 437 416
5,500 390 408
6,000 N/A N/A
6,300 N/A N/A

Group #2
PN 12-423-8
Grind XR276HR-10
Intake valve lift 0.502 inch
Exhaust valve lift 0.510 inch
Intake duration at 0.050-inch lift 224 degrees
Exhaust duration at 0.050-inch lift 230 degrees
LSA 110
Intake valve opening 32
Intake valve closing 64
Exhaust valve opening 75
Exhaust valve closing 27
Cranking compression 225 psi
Idle vacuum at 900 rpm 17.5 inches
Peak torque 486
Peak horsepower 462
Average torque at 2,500-6,000 rpm 455
Average horsepower at 2,500-6,00 0rpm 368
RPM   TQ HP
2,500 422 201
3,000 437 249
3,500 472 315
4,000 484 369
4,100 486 379
4,500 484 415
5,000 470 448
5,500 441 462
6,000 397 454
6,300 N/A N/A
Group #3
PN 12-443-8
Grind XR294HR-10
Intake valve lift 0.540 inch
Exhaust valve lift 0.562 inch
Intake duration at 0.050-inch lift 242 degrees
Exhaust duration at 0.050-inch lift 248 degrees
LSA 110
Intake valve opening 41
Intake valve closing 73
Exhaust valve opening 84
Exhaust valve closing 36
Cranking compression 200 psi
Idle vacuum at 900 rpm 7.5 inches
Peak torque 508
Peak horsepower 509
Average torque at 2,500-6,300 rpm 467
Average horsepower at 2,500-6,300 rpm 398
RPM TQ HP
2,500 397 197
3,000 411 235
3,500 465 310
4,000 498 379
4,500 508 435
5,000 501 477
5,500 480 503
5,900 454 509
6,000 445 508
6,300 414 496