No.
350 and 500 share the same case.
And the crankshaft.
600 ist something completelly different
The 600ccm crankshaft is about 2mm thicker than the 350/500 one. So nothing will fit.
The 500 Saturno case exists also in 2 versions.
The later one is somehow 'reinforced' I must somewhere have a pic of the differences you can see from outside.
Putting a 600 barrel on a Saturno bottom end should better base on the later case.
ciao joachim