Timing chains and eccentrics

There were three eccentrics used, too are thin, )one each cast iron and stamped steel 2 pc) Then another thicker eccentric. The cast eccentrics need a longer dowel pin that extends farther out from the cam gear to engage the eccentric. The 2 pc has a bent tab that engages the cam gear hole. As far as replacing one with the other for durability's sake, the 2 pc it seems would be the weaker of the two, but I've never seen or heard of either failing. They seem to last longer than the engine.
 
I was asking because I bought a timing chain, and tech support guy told me that for '73 sbf I needed timing chain for 1 piece eccentric (up to 1984). Timing chain's instructions however say that ford ended up with with one-piece eccentrics in '72, so I would actually need chain for 2-piece ecc. I just wanted to know if there is any way to adapt timing chain with 1-piece ecc where chain for 2-piece ecc should be once I get to actual instalation. Well easiest way is to buy both chains; maybe I'll do it to be sure