I checked the ground clearance on my previous Morgan - a 1999 +4 when I bought it when it was 10 years old. I suspected it was considerably less than the 100mm stated in the owner's manual. It turned out to be 70mm. (This was at the gearbox cross member). So it was no wonder the car became intimate with speed humps and other road irregularities.
It was due new tyres so I replaced the original 195/60/15's with 195/65/15's, which gave me a welcome 10mm extra ground clearance - and coincidentally gave a more accurate speedo too.
However, I gained a very welcome further 20mm clearance by shortening the rebound springs by 20mm (at zero cost) using an angle-grinder. This might sound a bit brutal, but it was a pretty straightforward job using the method given on the Go-Mog site to partially dismantle the front suspension. I removed the rebound springs, put them in a vice, and set to with the angle grinder, followed by a file to smooth off the edges. A big added bonus was that it also improved the ride quality considerably, making it much more compliant. So it might be worth checking if this modification would work for you, especially if you're considering spending nearly £1000 on the Suplex set-up, as it could save you a fortune!
(Check to see if you can rotate the rebound springs without too much effort with the car standing on the ground as normal. If you can, then this mod wouldn't give any benefit, but if you can't rotate the springs then it implies the springs are being unduly compressed at rest and could be shortened).
This then gave 105mm clearance at the gearbox cross member, and 124mm at the rear cross member just in front of the back axle.
