Personally, I would get these, I did last year when I installed my Q45:
Billet R230 CV Adaptor, 70-78 Z Car
Also, look at this kit too, again I bought this as well:
R200/R230 Viscous Differential Mounting Package
BTW: DON'T FORGET you'll need FOUR (4) Q45 inner CV axle assemblies
Here's my Q45 upgrade thread to give you some ideas/pictures:
Q45 upgrade