So I look up comp xe250h specs (I'd say good choice for mild 318) and ran it through the Wallace V/P DCR calculator, AJ got with stock 8.1 318, 140 psi 7.1 DCR and V/P 116, with the xe250h I got 137 psi 6.98 DCR and V/P 111 nothing to write about but for the power gain I doubt this slight loss would kill the bottom end but say it will if you install at Intake center of 103 vs 106 you'd have the same as stock psi dcr v/p or could go somewhere in between and this is the 1st cam I checked.
HORSEPOWER SUPERFLOW 901 DYNO-TESTED AT WESTECH | |||
RPM | BASE | MOD 1 | MOD 2 |
2,000 | 112 | ||
2,500 | 137 | ||
3,000 | 164 | 193 | 192 |
3,500 | 182 | 224 | 227 |
4,000 | 189 | 248 | 252 |
4,500 | 186 | 265 | 274 |
5,000 | 179 | 271 | 282 |
5,500 | 262 | 270 |
TORQUE SUPERFLOW 901 DYNO-TESTED AT WESTECH | |||
RPM | BASE | MOD 1 | MOD 2 |
2,000 | 292 | ||
2,500 | 287 | ||
3,000 | 287 | 338 | 336 |
3,500 | 272 | 335 | 340 |
4,000 | 248 | 326 | 330 |
4500 | 218 | 309 | 319 |
5,000 | 188 | 285 | 296 |
5,500 | 250 | 258 |