Dana 60 strength?

We built a blown and injected 496 Chevy big block to go in a Monza back about 1983. Power glide, Dana 60 with 4.10 gears on a Dana Power Lock and 33/19.50 15 slicks. It ran down in the 9.0s before the owner sold it. The new owner ditched the blower for a 1250 and nitrous and went into the 8s.

I don't know what kinda power it had, but the Dana never burped.