I'm rebuilding mine as we speak. I had to take a few liberties on the build namely for reliability and longevity. Rods for instance was one area I wasn't willing to reuse. After 46 years of use they could be fine, or maybe not. Even after machining and good bolts, I still didn't want to take the chance of one coming apart and taking out a numbers matching block. So we went with a nice aftermarket rod, much stronger and slightly lighter as well. The lighter weight is much easier on the rotating assembly.
Another liberty I decided to take, rather than use my NOS pistons for the build, we decided to go with an aftermarket forging. Lighter weight piston which again is easier on the rotating assembly when you spin these things up, but it also has other advantages like shorter skirt design and a smaller ring package for less drag.
I'm staying true to the nature of the engine however, compression will still be 11:1.
Heads are getting hardened seats, a good set of valves that are designed to flow a little better, and a good valve job, as well as cutting for positive seals for better oil control.
As far as the cam goes, I have a stock grind new in the box, but without a cam card, and after talking with the machine shop that is doing the work, he suggested we use a Comp copy of the cam, slightly modernized lobe profile but .050 numbers are the same at 254 and lift is the same, I think the lash is tightened to .024 rather than .030, and the same 114 LSA. My goal is to have the engine sound exactly like it should sound. I may play with the install position a tiny bit.
I find the stock cam very drivable myself, when I'm done tuning, and the way I like to run my timing curve and initial advance, vacuum advance etc....the stock DZ cam idles fairly smooth for me with only a slight hint of a lope when cold, as the engine warms it's hardly there at all. The biggest giveaway is the noise of the lifters.
I've heard other 302's run that are rather choppy and others that are smoother like mine. I chalk that up to either the owner has changed the cam, or the tune on the engine isn't as crisp. Myself, I can get the stock 30-30 cam to idle fairly smooth with 16 initial on the timing and some vacuum advance thrown in there as well, some carb tweaks, and some people would probably question if it's the right camshaft