Are you talking about your DZ 302 engine Larry? Didn’t DZ cranks use tufftrided forged cranks? I don’t recall SBC nitriding factory cast cranks.
With the lash not budging after 50K miles, with a combination of the edm oiling, on a nitrided SFT cam that isn’t overly aggressive, I think it will go a long time yet. It is just getting broke in.
.