LD 340 on a 318?

What if I put a set of X heads on the engine?#-o

I've been using an Edelbrock 2176 with a 600CFM carb. on the 318.

Just looking for a little more performance out of my 68 318. I was going to put a 69 340 in until I discovered that both engines make the same amount of torque (340), only the 318's torque comes on around 2400 RPM instead of 3200 RPM of the 340 engine. I figured that I was only gaining horsepower, correct me if I'm wrong, but isn't torque that propels the vehicle?:dontknow:

http://www.allpar.com/mopar/318.html

Any and all feedback/comments are welcomed, just want to get it right. I believe that I will with all your comments/guidance. Thanks all