How to Upgrade a 421 Small Block

Concealed Weapon

Steve Dulcich Oct 28, 2013 0 Comment(s)
View Full Gallery

Dyno Results
Chevrolet 421 Small-Block
DTS Engine Dyno Tested At Dr. J’s

RPM TQ HP
3,000 451 257
3,100 466 275
3,200 482 294
3,300 493 309
3,400 506 327
3,500 520 346
3,600 532 364
3,700 541 381
3,800 547 396
3,900 554 412
4,000 560 426
4,100 566 442
4,200 571 456
4,300 574 470
4,400 576 482
4,500 577 495
4,600 581 509
4,700 584 522
4,800 589 538
4,900 593 553
5,000 596 568
5,100 596 579
5,200 596 591
5,300 595 600
5,400 592 609
5,500 590 618
5,600 587 626
5,700 583 632
5800 583 644
5,900 580 651
6,000 579 661
6,100 573 665
6,200 569 672
6,300 563 675
6,400 557 679
6,500 549 679
6,600 543 682
6,700 531 677
6,800 519 672
6,900 506 665
7,000 494 658

Cylinder Head Airflow
SuperFlow 600 Flow Bench
Dr. J’s AirWolf 220
2.125 intake; 1.600 exhaust; cfm at 28-inch water depression

Lift Intake Exhaust
0.100 78 65
0.200 155 116
0.300 217 162
0.400 266 196
0.500 302 219
0.600 320 233
0.700 325 244
0.800 328 252
0.900 331 257
1.000 333 260

2/17

Inside the plenum, the detailed port work is revealed. In addition to high flow, the manifold is designed to optimize flow balance and fuel distribution.

Holley 950 Street Hp 3/17

For high-rpm power, a carb of sufficient capacity is a must. This Holley 950 Street HP offers substantial airflow and strong throttle response.

Chevy Small 4/17

When it was all said and done, this deceptively simple looking Chevy small-block delivered 682 peak horsepower at 6,600 rpm, and a phenomenal 596 lb-ft of torque at 5,200 rpm on 91-octane California pump gas. CHP

Sources

Automotive Racing Products
Ventura , CA 93003
800-826-3045
www.arp-bolts.com
Comp Cams
Memphis, TN 38118
800-999-0853
http://www.compcams.com
CP Pistons
Irvine, CA 92614
949-567-9000
http://www.cppistons.com
Cloyes Gear And Products Inc.
Ft. Smith, AR
479-645-1662
http://www.cloyes.com
Manley Performance Products
Lakewood, NJ 08701
732-905-3366
http://www.manleyperformance.com
Mahle Motorsports
Fletcher, NC
888-255-1942
http://www.mahlemotorsports.com
Professional Products
Hawthorne, CA 90250
323-779-2020
www.professional-products.com
Callies Performance Products
Fostoria, OH 44830
419-435-2711
www.callies.com
Melling Engine Parts
Jackson, MI 49204
517-787-8172
http://www.melling.com
Meziere Enterprises
Escondido, CA 92029
800-208-1755
meziere
Isky Racing Cams
Gardena, CA 90248
323-770-0930
www.iskycams.com
Moroso Performance Products
Guilford, CT 06437
203-453-6571
www.moroso.com
Dr. J's Performance
Orange, CA 92868
714-808-9780
www.j-performance.com
Holley Performance Products
Bowling Green, KY 42101
270-781-9741
http://www.holley.com
Dart Heads
Troy, MI 48084
248-362-1188
http://www.dartheads.com
Federal-Mogul
Southfield, MI 48034
(248) 354-7700
www.federal-mogul.com
HVH (High Velocity Heads)
Knoxville, TN
MSD Performance
El Paso, TX 79936
915-857-5200
http://www.msdignition.com/

COMMENTS

TO TOP