This time last winter, I had the sub frame out from the under the car and was going through the restoration process of everything from the front bumper to the end of the drive shaft.
I concur with JohnZ. I used poly bushing in my 69 RS and the car handles very well. It is stiffer, which in my opinion is very desirable. However, although stiffer, it is not harsh - just firmer and improves the handling quality of the car.
Good luck with your project.