Since these heads are Vortec...
Since these heads are Vortec style, we gained the improved sealing gaskets up top, but needed to be sure to order a Vortec-style Edelbrock AirGap intake, and also needed center-bolt style valve covers.
A 650-cfm Speed Demon carb...
A 650-cfm Speed Demon carb seemed like plenty for a 305, promising a good balance of low-end performance and top-end power. The full-throttle manifold vacuum peaked at under 1 in-hg. at the top of the dyno pulls, showing that it had plenty of flow capacity on this engine.
What was our "Power Pack"...
What was our "Power Pack" worth on the 305? How about 372 hp at 6,100 rpm? However you feel about 305s, you've gotta love that.
Engine Master Dyno Test
305 CID Chevrolet
901 Engine Dyno
STP Correction Factor
Tested at Westech
| |
|---|
| RPM | Stock TQ | Mod TQ | Stock HP | Mod HP |
| 2,600 | 285 | 290 | 141 | 144 |
| 2,800 | 283 | 297 | 151 | 158 |
| 3,000 | 287 | 320 | 164 | 182 |
| 3,200 | 291 | 328 | 177 | 200 |
| 3,400 | 290 | 334 | 188 | 216 |
| 3,600 | 284 | 337 | 195 | 231 |
| 3,800 | 279 | 340 | 202 | 246 |
| 4,000 | 271 | 346 | 206 | 264 |
| 4,200 | 264 | 349 | 211 | 279 |
| 4,400 | 256 | 349 | 214 | 292 |
| 4,500 | 252 | 350 | 216 | 300 |
| 4,600 | 250 | 348 | 219 | 305 |
| 4,800 | 241 | 344 | 220 | 314 |
| 5,000 | 233 | 342 | 221 | 326 |
| 5,200 | 221 | 343 | 219 | 339 |
| 5,400 | - | 337 | - | 347 |
| 5,600 | - | 330 | - | 352 |
| 5,800 | - | 324 | - | 358 |
| 6,000 | - | 322 | - | 368 |
| 6,100 | - | 320 | - | 372 |
| 6,200 | - | 314 | - | 370 |