I have great respect for all the Artists here on e621, and some images in particular I would find to be very interesting to see in 3D.

I've noticed some side-by-side Stareograph images here already, but I'd like to add enhance some already amazing work into something three dimensional.

Is it acceptable to do this and re post images in this format? or is that against the rules? (or otherwise improper?)

I don't see why not. The 3D guy did it and hasnt gotten his posts deletes...far as mt knowledge.

As long as you credit the original artist it should be fine.

It likely would be fine, but asking the artist would add an estra level of being sure :o

ALWAYS ask the artist first. If you don't, the artist may get mad, then he'll process a takedown request and then that image and his/her art will never be on e6 ever again ALL BECAUSE YOU DIDN'T ASK THE ARTIST FIRST. Oh yeah, and give the dude the credit