Harry, you need to have the block checked out by a competent machine shop before you do anything. They will evaluate cylinder wall wear and taper, and then advise how to proceed. At a minimum it will require being hot-tanked, honed, and will have to have new cam bearings and freeze plugs installed. You cannot install the cam bearings yourself with the appropriate equipment.
Having 40+ year old rods resized will cost almost as much as buying a new set...some shops will even charge more than what a new set goes for. Shop around and get a good set of H-Beams. Ignore any drunken, late nite, ebay shopping urges to pull the trigger on any of the SIR rods, no matter how good the deal looks. They are junk.
Hypers are okay for a budget build. I prefer forged in anything I build, but I have run hypers before and don't have anything negative to say. Follow the manufacturer's recommendations for cylinder wall clearance and ring end gaps for whatever you end up with.
The MoPar Purple Shaft cams were great about the time that you were in junior high school. Cam technology has advanced by leaps and bounds since then. Would you consider a Tandy TRS-80 if you were shopping for a new home computer? I doubt it. Don't put a Tandy TRS-80 bumpstick in your engine. Look at the Comp Cams Xtreme Energy line or the Lunati Voodoo line if you're sticking with a hydraulic flat tappet which I assume you are. There are about 100 threads on this site alone about camshaft selection for a street car. Do a search and read up on what has already been written.
I'm sure you'll have more questions for us, but I think I have covered the ones that you posted most recently.
