Engine and Transmission Tech

i need to buy some piston rings for my olds 215 and i have never bought any before so what are the good ones the machine shop guy told me something about molys but i don't remember what he sied if it was good or bad

I recommend Moly rings. I use a regular stone type hone and then go over the bores again with a ball type flex hone.

It depends upon your intended use Tristan.
Cylinder bore quality also will influence your choice.
for a street engine, if the bores are not new and straight. Your only real choice is a good old fashioned cast iron ring set with a three piece oil ring. My preference for honing is a good, old school, straight stone hone. The ball style hones produce a beautiful finish but they follow all the cylinder irregularities and do nothing to help even out the bore. Having said that, you are only resurfacing the bore. If you are trying to remove scores, rust marks deep scratches grooves etc. then you really need to do a rebore.
Moly rings are a good all around choice if the engine has a fresh straight bore job. And is used in a clean environment. No open air cleaners etc. The moly will pick up the dirt and beat your bores to death with it. There are several ways to produce a moly ring and some are better than others. Educate yourself and buy the best quality ones that you can afford. Lastly, moly rings generally don't tolerate detonation very well and will flake, wrecking the cylinder
That brings us to chrome rings. These are the toughest general use rings but they wear the bores faster than the other choices.
They also take forever to break in. Their ability to tolerate dirt and detonation makes them worthwhile in harsh environments within reason.
There are many other ring choices available but these are the three most common.
Lastly, consider plateau honing for your new cylinder bores. But only if your machinist is "very" familiar with the procedure.
Just my opinion but I hope it helps some.
Cheers
Fred