I don't think you understood the question. They would, of course, have to be new rails of the proper height, but no pockets or pocket shelves would be involved, since we're talking about a carom table.
I only ask because our senior center had one of those dual use tables that Brunswick used to make that had both carom rails and snooker rails. It was set up as a snooker table but fortunately we had the carom rails available and it was a pretty straightforward deal for the mechanic to take off the snooker rails and put the carom rails (with new rubber) on with everything recovered with Royal Pro cloth (since we were not retrofitting a heater).
So it seemed to me that if new carom rails were made (which, of course, would be made to the proper height) the table could be easily converted without having to cut or grind the slate.