That would be the best way to go with out having to re-do much. A friend up here with a built 455, E-Heads, large cam etc installed a fluid assist system that runs off the Power Steering Pump. Looks awesome, and he said it works great!

But then you are having to red do some of the lines, add some hoses etc... more work and more expence etc.

Check out a vacuum can first?

Brett - 67 Drop Top 455!