I currently have manual steering in my 67' 440 Belvedere and am counting the days until I swap to a Firm Feel box. I did it in my 71' Duster 340 I had and found for a cruiser it was just more relaxing to drive.

As a side note I firmly believe the faster ratio of the power box saved me from an accident in the Duster when someone cut across in front of me. With the slower 24:1 of the manual box there is no way I could have swerved in time to keep from T-boning the little old lady.