383 intake / carb help for my 73 Dart

Hey guys . . . .
I have a 70 383 4 bbl in my 73 Dart. It's just a cruiser. The guy I bought it from didn't know anything about it but that it was a "383 with a mild cam". Haven't opened it up and really don't plan on it yet. I have found it is a 1970 383, has a Holley 1850-4 4160 carb, a "Streetmaster 383" intake, and exhaust manifolds. Carb needs a rebuild and I know nothing about the intake. Can you guys give me some ideas and direction? Is this Holley any good, would it be better to replace it or just rebuild it? What is the Streetmaster 383 and is it good for street use? My brother-in-law sez it is the wrong setup. It has the spread bore manifold and the square Holley pattern carb on it (could this be universal to both? He sez go back to the stock manifold and rebuild the carb. I want it to cruise well without getting too crazy. Your comments are welcomed & appreciated. Rog