Although there are cams that will make more horsepower than what I'm going to show here from a DynoSim, in my opinion they make insufficient low end torque to make a good street motor. CompCams 08-450-8 made 522 hp @6000, but the torque was down 21 ft/lbs at 2000 over this 08-423-8 I'm using in this DynoSim. This cam has a short lift when used with 1.5 rockers, so valve spring life should be good and the whole thing should be easy on parts while still eclipsing the 500/500 mark I like to see in a 383. This is an extreme energy grind, so I would hesitate to use 1.6 rockers on it. No use asking for trouble on a street motor.

I used AFR 180 Street heads and CFM of 1000, figuring you will use two 500 CFM carbs. 1 3/4", long-tube, equal-length tuned headers through the mufflers were used in this Sim. AFR 195 heads didn't show but another 5-7 hp and ft/lbs, so I used the 180's, figuring that I would rather have higher velocity in the runners for better throttle response.

The cam was installed straight up, neither advanced or retarded. With an intake closing point of 38 degrees ABDC and your 9.7:1 static compression ratio, a dynamic compression ratio of 8.43:1 was achieved. This should allow operation on pump gas if you use a good, tight (0.035"-0.045") squish. Here's the cam card.....
http://www.compcams.com/Cam_Specs/Ca...?csid=188&sb=0

RPM HP TQ
2000 148 388
2500 187 394
3000 242 424
3500 308 463
4000 371 487
4500 430 501
5000 471 495
5500 501 478
6000 506 443
6500 481 388