How to improve torque in my 68' impala?

I am restoring a 68' impala 4dr, and i was just going to go for horsepower but I was told that torque is the way to go. So I was wondeirng if it is possible to get alot of both without making the car ilegall to drive on the street. I was originally going to make the 327 in the Impala around 500hp could I keep it like that if i was also looking to improve torque. Also what is the benifit of having alot of either horspower or torque, or both for that matter, i know im not going to be doing any wheel stands while keep the car street legal.