I've got a GM 5140, 454 crank if you need one cheap. It's .030/.030.
Uses the internal balance flexplate (has a weight welded on the rear flange), but standard external balancer.
Double keyed for a blower.
It was .010/.010, but I had it sitting under a shelf that had a 1 gallon container of car wash concentrate above it. The container cracked and leaked all of that shit all down the crank.
Chaffed my ass having to take .020 off of a perfectly good crank due to surface rust.
Still has a few minor pits, but nothing that's going to hurt anything. It's freshly turned, well oiled, and sitting in my basement next to the dehumidifier. Been sitting here for about 18 months now, and still looks like it did the day I picked it up from the machine shop.