LS1/LS6 Head flows
Ported/Non-Ported
| Without Manifolds - Headflow Only | |||||||||
| Cylinder Head |
Stock LS1 |
Stock LS6 | Ported LS1* | Ported LS1** | Ported LS6 | ||||
| Intake Manifold | N/A | N/A | N/A | N/A | N/A | ||||
| .200" | 137 | 156 | 144 | 164 | 159 | ||||
| .300" | 187 | 204 | 200 | 217 | 212 | ||||
| .350" | 207 | 225 | 225 | 234 | 236 | ||||
| .400" | 223 | 243 | 245 | 253 | 255 | ||||
| .450" | 228 | 257 | 261 | 270 | 272 | ||||
| .500" | 237 | 268 | 272 | 284 | 300 | ||||
| .550" | 242 | 275 | 283 | 296 | 307 | ||||
| .600" | 243 | 278 | 292 | 305 | 314 | ||||
| Cylinder Head |
Stock LS1 |
Stock LS1 | Stock LS6 |
Stock LS6 |
Ported LS1** | Ported LS1** | Ported LS1** | Ported LS6 | Ported LS6 |
| Intake Manifold | LS1 | LS6 | LS1 | LS6 | LS1 | Truck | LS6 | LS1 | LS6 |
| .200" | 136 | 136 | 156 | 154 | 141 | 163 | 166 | 156 | 153 |
| .300" | 184 | 186 | 199 | 204 | 185 | 206 | 211 | 199 | 202 |
| .350" | 200 | 206 | 212 | 220 | 205 | 224 | 229 | 217 | 222 |
| .400" | 214 | 223 | 224 | 235 | 222 | 237 | 244 | 230 | 241 |
| .450" | 222 | 227 | 232 | 247 | 232 | 249 | 257 | 242 | 257 |
| .500" | 227 | 236 | 238 | 257 | 241 | 262 | 269 | 253 | 270 |
| .550" | 229 | 241 | 243 | 263 | 251 | 265 | 277 | 263 | 280 |
| .600" | 235 | 242 | 247 | 265 | 258 | 270 | 283 | 268 | 289 |
| * Original Stage II heads from New Dog, Old Tricks; GMHTP May/July 2000 | |||||||||
| ** Latest revision. | |||||||||
| Info originally from Chris Endres | |||||||||