There's no single answer to when a 327 cubic inch engine was "put back" into pickup trucks. The 327 was never a common engine in pickups to begin with, unlike its use in some Chevrolet passenger cars. Chevrolet never offered a 327 in their full-size pickups as an original equipment option. Therefore, there was no period to mark a return.
Any 327 in a pickup truck would be a result of a custom or aftermarket installation, meaning it would depend entirely on the individual who performed the swap.
