GMPP 383CI
1. Brodix dual-plane manifold with 4150 carb base fitted with Holley 750-cfm carburetor. Kansas-like torque curves for everyday grunt and upper-rpm flexibility were abundant.
2. The camshaft took advantage of the Brodix 200cc heads. We swapped out the springs, locks, and retainers to avoid valve float and to increase our rev potential. We swapped in Comp springs (PN 26120), locks (PN 795-16), and retainers (PN 613-19) for more open/closed seat pressure.
3. Comp 7.300-inch-long pushrods (PN 7949-16) push the Comp hydraulic rollers we have in place with H-bars. The pushrods are heat-treated chromoly with 0.080-inch wall thickness.
4. As usual, we relied on a Pro-Billet MSD ignition distributor (PN 85551) and wires.
5. Expelling fumes were Hedman 1 3/4 x 3 1/2-inch dyno headers with 18-inch collectors.

THE PROOF
Compression ratio 9.75:1
Fuel 91-octane
Timing 37 degrees
Spacer Wilson tapered
4-hole combo
Max torque (lb-ft) 456 @ 5,100 rpm
Max power (hp) 466 @ 6,500 rpm
Avg. torque (lb-ft) 424
Avg. power (hp) 382
RPM LB-FT CHP
3000 389 222
3100 387 229
3200 390 237
3300 397 249
3400 408 263
3500 415 277
3600 422 289
3700 427 301
3800 432 313
3900 437 325
4000 440 335
4100 442 345
4200 445 356
4300 447 366
4400 449 376
4500 449 384
4600 448 392
4700 447 400
4800 446 408
4900 447 417
5000 447 426
5100 456 433
5200 442 438
5300 440 444
5400 436 449
5500 433 453
5600 429 457
5700 424 460
5800 419 462
5900 414 465
6000 408 466
6100 400 465
6200 394 465
6300 388 464
6400 382 465
6500 376 466