I have a rear mounted power R&P set-up in my 56 Customline, but I have to say it was a nightmare and without help from an engineering professor at Boise State University, I probably couldn't have made it happen.
About 7 or 8 years ago there was a guy,Rick Wurth,(Wurthit Designs) who advertised a rear mounted R&P set-up for 55-56 Ford passenger cars using a Cavalier rack that mounted with his kit. The big problems that were encountered were that he did his mock-up only on automatic, non Y Block powered cars. So, after we had the rack mounted and put the motor in, the oil pump rested squarely on top of the rack requiring the motor and tranny to be shimmed up 1/4" off the motor mounts. As Ted stated, the angle coming off the column was extreme and a complicated heim bearing and bracket had to be fabricated to ease the angle and to get around the clutch linkage. We did finally get it all to work and the car steers very easily. I have all the pictures of the nightmare trial and error process when we were building the car, but they are on my other computer which is packed-up for the move. My final words on this would be "don't try this at home"

Rono
Ron Lane, Meridian, ID