I called anyway.
The one is a 555 with 355 heads that made 807hp @ 6800rpm (engine dyno) with 8.75-1 compression. The other I think is 540 with 345 heads 11.xx something compression and made 795-798hp @ 6500rpm. I used 355AFR's on my 581 but I have a blower and wouldn't have gone quite as big had it been NA.