Lifting stuff up and over my tailgate (>30 lbs) has become a real problem. Age and the sins of my youth are catching up, been told I need both knees and left shoulder replaced. I have seen pics of swinging tailgates and am interested in doing this. My truck is a '66 C10 SWB stepside. Have some ideas how to do this but wanted to check this forum to see if anybody has done this and their process.
As an older fella I get your point. While I appreciate the "cool factor" of a right or left side hinged tail gate you still need to lift stuff the same height to get it to the level of the bed floor, thus the modification you are contemplating doesn't result in any advantage based on vertical lift height. Don't lift it "up and over the tail gate", simply lower the tail gate first. Make any sense? What the General (motors) hath made let no man put asunder...
maybe my choice of words was incorrect. dropping the tailgate, placing the cargo on the tailgate, then SLIDING it into the box doesn't appeal to me. i also like the cool factor.
Part of the issue will be supporting the weight of the tailgate. The bedsides will not be structurally strong enough as is. I widened the bed on my stepside and in the process added bed jamb using 1" x 2" tubing and 2" angle to the sides of the bed. This made the bed sides incredibly strong as it ties in the bed sides to the strong cross sill across the back of the bed. Perhaps this would work for you also, except you would need to shorten your tailgate. Here's a link with some information, start on post #10: https://talk.classicparts.com/showthread.php?t=13928