Here's what Desktop Dyno did with my stock 330HP Indmar 454:
RPM HP Torque
2000 160 420
2500 203 427
3000 248 434
3500 282 432
4000 302 397
4500 305 355
5000 283 297
5500 245 234
6000 195 170
.480" lift factory cam (.480"I, .472"E) 8.5:1 cr Large Oval Port heads, the small valves (2.06/1.76)
yours is probably similar.