As part of the mechanical restoration of GTC 9593 i had the suspension refurbished. New Konis, new ball joints and new bushings all around. By replacing these worn out parts the car's handling was completely transformed.
Although I made other upgrades to the car [cooling, electrics, a/c] I left the suspension stock. The car handles quite well with predictable initial understeer and throttle controlled oversteer. As Onno noted make sure the alignment is correct as this certainly affects the handling characteristics.
When you get the suspension rebuilt it will feel completely transformed. It's a fun car to toss about.
Current: SA, 330 GTC, Dino, BB, QP
Past: GTC, BB, QM, C/4, 355, 360, 550, 575, C/4