Mine did it in 5.5 on some timing gear once, so yea, you can do it.
I think the later versions were rated at about 5.2sec to 60. Think C&D got 5.1 out of a stock one (again on timing gear).
ZR1s or ones with the LT4 were all sub 5sec cars (when shiny and new), but the real differences were in the midrange and 100+ onwards acceleration.