Well..since I had a 376 in my 79, I'm pretty sure the modern stuff is plug and play. The OP juat needs to acquire the cruise package ( wiring) which allows him to integrate the 383 into the car. I'm assuming that the OP is either putting an HT383.
However if its an HT383..Chevy has its install kit:
HT383 Install Guide-Chevy Performance
If its like the 79 Z/28 I put a forged-stroked 376 CI engine into......you'll spend a small fortune on the incidentals.