Robbie seems to have covered everything, though I guess GoMoG will have a fair amount of data on spring choices..?
I seem to remember that over the years there was some sort of problem with sets of "weak" springs being fitted to new Morgans, where the drivers side would sag more than the other side and in a short period of time..? I think there was chat that some springs may have been sourced from India and of suspect quality, though my memory is not the best..
I have six leaves on my springs, and have only ever driven that set-up, which was chosen as my +8 was built with touring in mind and covered many a mile fully loaded with a heavy case sitting out on the rack..
Have to admit when I bought into the idea of a Morgan, comfortable springing was not high on my list of reasons for acquisition... (-: I have read of all sorts of efforts in suspension modification, and fixing extra ironmongery to the Trad in an effort to apply more modern expectations of comfort, and is perhaps to be expected as we age/evolve.. My springs are at least 20 years old, though perhaps only circa 30k miles of usage, but show no obvious signs of sagging and the Mog sits pretty evenly.
I guess within the limits of restricted travel of the axle given the the depth and number of of pot holes on our roads, comfort in a Trad would seem to be a relative term.. (-:
Good luck in your choices.
