McCullum's sparkling 224 guided New Zealand to a commanding 503 in their first innings before the hosts reduced India to 130 for four at the send of second day's play.
But McCullum said he had never imagined that the Kiwis would reach the 500-run mark after they were reduced to 30 for three in the morning session of first day's proceedings yesterday.
"We have bowlers to take 20 wickets if we give them enough runs and I think we have given them enough runs," said McCullum, after the second day's play was called off early due to bad light.
McCullum opined with India opener Murali Vijay and said the new ball was creating problems for the batsmen initially.
"So, to get two wickets in the first over was outstanding, especially (Cheteshwar) Pujara's wicket because he can bat for weeks. It's nice to get him pretty early. They had a nice partnership going in the end, but it means that we still have a hard ball tomorrow morning. There is a slightly earlier start and I am hoping for an overcast morning with some swing," he added.