Heres our Jensen. Weighs 4200 pounds. Has approx 700# springs on the front and 600 in the rear to keep it tight.
I would bet you will have to do some various frame or chassis bracing and mods, maybe a roll cage to stiffen the car up proper.
Is that car a Renault?
Looks like a neat project that will make for a very neat car when its finished.
Go for it if you have the time to invest!