I have embarked on a rebuild project that started as replacing the opti-spark and is now totally out of control

After taking all the top-end and front off leaving the short block, the engine builder mentioned I have come this far I should pull the engine hone block, replacerings, and oil pump.

However, I am considering installing a 383 package, has anyone done this? What kind of HP increase going to the 383 vs 350?

So far here is where I'm at in my quest to freshen up my engine;
Cam - Comp Cam 07-503-8 - 224 -230 112 deg lift intake .537 exhaust .544
Rockers - Scorpion Roller Self Aligning Narrow Body 1.6 Ratio
Lifters - Comp Cam Rollers 850-16
Heads - Port & Pollish to 195 flow
Intake - Match Ported & Pollished
Throttle Body- Holley 52mm
Fuel Injectors - 30# Ford Racing
Water Pump - Electric Mezirie HD
95-96 Style Opti-spark