Hi.
By flip I assume you mean rotate them 180 degrees so the bottom is the top?
If so, sure, but it would be a very bad idea. The axles on my SS are fine, and it's a '64.
It was the brakes and leaf springs that I had to replace. If you'll allow me to attempt to get inside your head... you want to raise the trailer up? You can do that by changing the leaf springs, adding shims, bigger wheels and tires... your post is fairly vague. So...
Post pics, explain your reasons, find Tom Patterson. Here is a gift for you:
http://tompatterson.com/Silverstreak...s/SS%20IOM.pdf
Here to help.
Ian