what year 383 you working with?

For best bang for the buck: If the short block is good, I would just change out the top end with the 440-Source stealth heads and an Edelbrock performer RPM airgap intake and maybe use an Edelbrock carb.

Here is my thinking: The stealth heads flow like the edelbrock heads, but the stock sparkplug placement allows the use of manifolds or standard headers. The TTI Edelbrock headers are nice, but really expensive. Also the smaller chamber size of the aluminum heads will increase compression ratio. The performer RPM air-gap manifold is about the best manifold (from 1500-5500 RPM) avaliable for the "B" block engine. The Edelbrock AFB or AVS style carbs work good and cost less than a simular Holley carb.

The stock '68-'71 magnum cam is actually a decent grind for a near stock engine/chassis combination.
If you plan to replace the cam, there is a wide range of cams avaliable depending on what your application is and if you plan to replace stuff like the gearing, torque converter, etc.

The HughesEngines HE2328BL is about the largest cam you can use with the valve springs supplied wit the stealth heads. The Stealth Valve springs have 130# seat pressure and 300# pressure at 0.485" lift. The Hughes 2328 cam is 223/228 duration @ 0.050" with 111 LSA and 0.506"/0.524" lift with 1.5:1 rocker arms. Also, if you use a larger cam, with stiffer valve springe you should replace the stock rocker arms.
The hughes cam is simular in duration to the Comp XE268H.