Out of curiosity,
Which is the better action a 1640 or a Pre-64 to build a 9.3
I guess that it would depend on which action you prefer.
The 1640 donor would probably be a little lighter, have alloy bottom metal, and be less expensive than a pre-'64 Model 70 donor. Simpson, LTD, in Galesburg, IL, is probably the biggest importer of used Husqvarna sporting rifle and may have a rifle with a good HVA action, but a poor/fair barrel and/or stock, that could be purchased for a better than average price.
My 9.3x62 has a Lothar Walther barrel on an Interarms Mark X with a mannlicher stock.