440 vs 360 GO!

I have a 73 scamp with a 360/727 that I suspect has been rebuilt but i think the cam was installed retarded. I am debating pulling the motor (fix oil pan leak) and swap the cam (ill end up needing heads too) vs buying a 440/727 out of a van and doing a big block swap. I love the looks and torque of a big block. Any input on best route? I know the big block weighs more but is it much more?