Although the lifter bore hone procedure could be done at home, it is very messy. You need a constant bath of honing oil to get good results. Generally done in the cylinder hone cabinet at a machine shop. Precision, flat stone rigid hone is an expensive tool. Mine was around $1200.00 10 years ago. I would guess the tool is in the $1500.00 range now. It will produce , straight round bores though. As far as proper bore geometry to the crankshaft/camshaft centerline, hopefully the original bores were bored with a squaring fixture for that purpose. Again the tooling is made by BHJ and called "Lifter True". The work is done in a vertical mill with the fixture. The fixture is engine platform specific. They are about $3500.00 for a basic kit, plus an additional $1000.00-1500.00 for each engine platform you want to use it on. Without a fixture like that, the only way to get the bushings in correctly would be to have a CNC lifter bore program for a 5 axis machine. Actually, could be done on a 3 axis machine if you had one and a program for a Pontiac. It's a big job either way.
I would not recommend sizing anything with a ball or flexible hone.
http://www.bhjproducts.com/bhj_conte...ooling/lbh.php