1971 340 Build - Choosing piston rings dilemma

Hastings I like and have used in about everything.. I just put a set of those in a 340, havent run it yet. Was the steel ring vs iron diff in the set I bought. I wanna say they were 70 bucks. I'll try to dig up the part #

Those are a brand I usually look for on eBay. I try to find good deals on older NOS American made brands. Had good luck so far. ......and gotten some really cool old boxes too. lol