Early Gbody studs are .564 knurl. 46160 is the correct part for Gbodies with 7/16 studs.
If you can't run the long studs, there is some from a newer mustang, 2012 I think, maybe newer, that were about 1/2" longer IIRC. The only place I could have got them was at the Ford dealer, and I didn't even bother asking.
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