I have 3 Morgans a '61 DHC, A'63 +4-4Str and a +8 Bitsa built on a '98 chassis. I have also driven quite a lot of Morgans but not anything newer than 2005. They are all different so far as ride and comfort. The '63+4 is the best. The +8 is the worst. I have installed the front Suplex Kit on all 3 of My Morgans. It is now on the DHC and I like it. The '63 +4 is original suspension so far as I know. It has Koni shocks on all 4 corners. I have more theories than I can count as to why the difference. I think (THINK) that the front and rear hoops take out some chassis/body flexibility on the newer models. Actually probably a good idea based on how We drive these cars today. As far as spring over rear suspension I drove a Issis Motors +8+ for 4 days. It was OK. It was a borrowed Morgan and I minded My manners.
As I am old it takes Me forever to get to the point. I think the 5 link must be bolted into Your current Morgan in order to ascertain if it is a fit or not.