POWER RECAP
For this dyno test we thought we could do a little better by installing a set of Vortec cylinder heads and trying COMP Cams Magnum roller tip rocker arms. Our 355-cid small-block clocked in at 422 peak hp and 452 lb/ft of torque. Average horsepower and torque were at 339 and 426, respectively.
MOTOR SPECS:
GM four-bolt, 355-cid, 9.4:1 compression, GM Vortec iron heads (SDPC PN SD8060A, 64cc chambers, 170cc intake runner volume, 1.94/1.50 valves), COMP Cams 1.6:1 Magnum roller tip rockers (PN 1418-16), Edelbrock RPM Air Gap Vortec intake manifold (PN 7516), Speed Demon 750 carb, 1-inch open carb spacer, COMP Cams XE262H cam (262/270 adv duration, 218/224 duration at .050, .462/.469 valve lift, 110 lobe separation) straight up, 1 /34-inch Hooker headers, 91-octane Shell Unleaded fuel
| VORTEC POWER |
| RPM | TQ | HP |
| 2600 | 399 | 198 |
| 2800 | 408 | 218 |
| 3000 | 421 | 240 |
| 3200 | 430 | 262 |
| 3400 | 436 | 282 |
| 3600 | 440 | 302 |
| 3800 | 444 | 321 |
| 4000 | 448 | 341 |
| 4200 | 451 | 361 |
| 4400 | 450 | 377 |
| 4600 | 443 | 388 |
| 4800 | 438 | 401 |
| 5000 | 431 | 410 |
| 5200 | 421 | 416 |
| 5400 | 409 | 421 |
| 5600 | 396 | 422 |
| 5800 | 373 | 411 |
| Max | 452 | 422 |
| Avg | 426 | 339 |
| 355-cid VORTEC SPECS |
| Bore / Stroke / CID: | 4.030 / 3.48 / 355 cid |
| Compression: | 9.4:1 |
| Block: | GM factory four-bolt 350 |
| Crank: | SCAT cast-steel PN 1101-11133 |
| Pistons: | Probe forged (PN 130212334-030) |
| Rods: | Probe (PN 1201-10062) 5.7" |
| Rings: | Total Seal Moly |
| Bearings: | Clevite |
| Gaskets: | Mr. Gasket and GMPP |
| Cam: | COMP Cams (XE262H) 218/224 at .050, .462/.469 lift, 110 LS |
| Lifters: | COMP (PN 858-16) |
| Chain: | COMP (PN 2100) |
| Pushrods: | COMP (PN 7372-16) |
| Rockers: | COMP 1.6:1 (PN 1418-16) |
| Heads: | GMPP Vortec (Scoggin-Dickey PN SD8060A) |
| Manifold: | Edelbrock Performer RPM Air Gap (PN 7516) |
| Carb: | Demon (PN 1402010VE) |
| Distributor: | Pertronix (PN D1000) |
| Spark Plugs: | Autolite AR103 |
| Oil System: | Milodon HV (pan PN 31505) |