If you decide to hone the block make sure and use a spray on lubricant to help flush the metal out and keep the stones clean I use a garden sprayer and a mix of diesel fuel(1 gallon) and 5W 20WT motor oil or 1 quart of ATF as the lube
As far as how long on each cam journal it will depend on how much pressure and RPM your using on each journal Make sure and use a good quality 1/2 inch electric drill motor, not a cheapo 3/8 size EDITED Make sure and stroke it front to back equally so you don't wear a groove into the stones, it would be easier if you had a way to control the stroke length and center the shaft to the hone so it doesn't wobble around a lot while honing
Take your time on the first one, cut a little at a time and the measure again until you get it within .0005 on the small size and go from there
I'm thinking it will not go fast so be patient and take your time, good luck