I'd be wary of the original Fiat/Alfa wishbones right now.
I tried fitting 3 genuine Fiat wishbones to my coupe (same wishbone as the GTV) and at least 2 nuts stripped on all 3 wishbones, even those supplied by my local Fiat dealer and even when new bolts were fully screwed in by hand before tightening.
The Coupe service manual says the wishbone bolts should be torqued to 69Nm, the GTV manual says 59-72Nm, but sometimes all 4 nuts would strip *way* before even 50Nm. Seems they have a problem with the nuts being made of cheese!
I also tried a Delphi wishbone but the nuts on it were about 2-3mm out of alignment and so that one failed to fit as well. Eventually got Lemforder wishbones form Eurocarparts and those were fine, fitted and torqued up OK.
All 4 nuts on the rusty wishbone I took off (not sure of it's origin), the Delphi and both Lemforder wishbones would take 69Nm no problem. On the 3 Fiat wishbones I tried at least 2 and sometimes all 4 nuts stripped long before reaching 69Nm.