There are a bunch of hones out there. I've found the best thing is to use some green scotchbrite over the stones of a flex hone (rigid stones) and I use wd40 as cutting oil. It really only removes the glaze and the new rings (moly) seat quick and seal well. I've done it on several newer 4cyls and a 383 before with excellent results. If you really "hone" you can create more issues with ring seal long term than you fix. Most drill type hones are too rough for todays rings.
Comments are correct, you are seeing normal carbon deposits on a well-worn, low compression 383. A real low budget rebuild would include knurl pistons and refit, lightly hone cylinders with new rings, new crank brgs, new cam brgs, new timing chain, new cam, rebuild heads, all new seals and gaskets. Any thing less is not worth the risk.
I've used this several times as well. I used it on my late Mom's Valiant 6 that was REALLY carboned up(imagine how slow an 80 year old lady drives!). Trickled water down the carb while revving the engine...you should have seen the crap that came out the tailpipe!...and boy did it run better afterwards!
Not knocking this technique, but I'd be more inclined to buy a can of Seafoam and use it before introducing water into an engine internally.
Just MHO.