Yes, it is!

Bis's (Cinquecento 700) crankshaft was designed for 700cc and 50Nm. Harder and better balanced in high revs. The standard 650 comes out of the first 500 or maybe the Nuova Sport (I'm not sure if there are different crankshafts). According to the logic and the tuners it's OK for more power. The stroke is still 70mm. (Here was described, but still not working...
http://maluch.mgt.prv.pl)
About the standard 263* camshaft (timed like Panda 30 with 5* difference 21/62 - 61/22), it looks similar to the Kent Cams RT200 for Renault 5 GT Turbo 20/64-64/20 (264*)

Some of the standard Fiat 500 shafts are with shorter opening, so maybe they could be better in some applications. The 650E one isn't good for turbo, cos the exhaust phase is longer.
The 650E has better combustion chamber shape. Also the c.r. is 8:1 compared to 7.9:1 in R5 GT Turbo. Valve diameters in the Renault: 34.3 mm inlet ; 28.9 mm exhaust and ours 33x28.
There is lack of info, so I'm just comparing, hopping that someone skilled will teach us
Greeting!