The SCAT and Eagle cranks are off-shore cranks, not made in USA. I'm running a 400M crank in my 408 stroker and that thing is solid. According to my father (metallurgist), Ford used really good material in their cast cranks. In fact, they produced the strongest cast cranks ever back in the 60s and 70s. The professional drag guys back then used to run a stock 351C high nodular cast iron crank in the low 9s and 10,000 RPM (with oiling mods, of course). Detonation is the number one killer of a cast crank.
I run a 400M crank, Chrysler 360 rods rebushed, shotpeened, polished, etc. at 12:1 compression in a C90E block that puts 550 horse and 580 ft-lbs of torque to the pavement. I don't spin it past 6000 and it seems to be fine. I did put a girdle on the block, though. I also made sure that the main caps were perfectly align honed and every oil clearance was perfect. I have spun a rod bearing on this combination before.
'89 5.0L LX hatch: all 90mm 2.2L Blowzilla Dart Iron Eagle 306 @ 8.4:1, ported Vic Jr heads, TMoss ported GT40 lower, Deka 80# injectors, EDIS8, GUFB-A9L2-Moates tuned, Tremec 3550, 3.31 gears w/31-spline TruTrac
'66 GT 2+2 Fastback: carb'd 289, Canfield heads - EFI transformation pending
'71 Mach 1: totaled - R.I.P.