If the cylinder is round, and the taper is less than .005", hone the cylinders, clean them up THOROUGHLY with a stiff-bristled scrub brush and HOT soapy water, and re-ring the engine. If the cylinder is egg-shaped anywhere or the taper is more than .005" bite the bullet and rebore it. The most cylinder wear occurs in the top 1 1/2" of piston travel where the combustion pressure is the greatest- - - -it doesn't progress gradually from top to bottom, so where the rings need to seal the best, they're least likely to be able to do so in a taper-worn cylinder.
I have used a rigid hone to take out 3-4 thousandths of taper, and then put a knurl on the piston skirts to take up the extra clearance. That was an oldtime procedure we used back when a re-ring job only lasted 30-40K miles, and some engines got one or two in the frame overhauls before getting rebored. Perfect Circle used to sell a piston-knurling tool called a "Nurlizer" that could be used for that purpose by small shops without a lathe. It's possible to expand the diameter by .002"-.003" with a knurl on the thrust face of the piston skirt to avoid piston slap after a hone job.
Jerry
