I've done it. Years ago, I put power windows in my Bobcat (Mercury version of Pinto). I simply took the power window regulators from a Olds Toronado (or similar vehicle, don't remember exactly) and laid the power regulator over my manual regulator and marked them. Then I cut off the ends of the power window regulator and then cut off the ends of the manual regulators with enough extra length to bolt them to the base of the power regulator. Worked great. I think it was the only power window Bobcat on the planet
. Good luck with the project and let us know how it works out. I am going to be doing a similar project on my daughter's '57 pretty soon.