As others have said, if building a 383 for street use (and maybe a trip down the strip or two) you'd be well advised to go with headers, a 2.5" (min.) diameter mandrel bent exhaust system with an "H" or "X" pipe and some free flowing mufflers, some mild head work including a multi-angle valve job and hardened valve seats (pre '74 heads) for running today's unleaded gas, a mild cam like Comp's XE268H, Hughes Engines HEH1019BL or the Lunati Street Master 07301 (even though I'm not a big fan of the single pattern cam for street use), a dual plane intake manifold (MP M-1 Dual Plane, Edelbrock Performer or for more power an Edlebrock Performer RPM - just be aware that you'll need a drop base air cleaner for hood clearance with the RPM intake) for good low-mid range torque, a Holley 650 or 750 dual feed, vacuum secondary carb or the Edelbrock Thunder AVS (650 or 800 cfm). If its to be strictly a street car then go with the 650 cfm carb size as this will keep air velocity in the intake circuit high and give you more "seat of the pants" feel - as well as give just a bit better fuel economy than the larger carbs.
Don't forget the rest of the combo. You'll also need a good stall converter (about 2500 rpm or so), a mild trans shift kit, a decent aftermarket transmission cooler (if the car is an automatic) and 3.55 gears for good around town driving and highway cruising. 3.91 gears are a bit much for highway use but sure do feel good around town! They'll also set you back in the wallet, though, as they are a bit hungrier than the 3.55's.
