I have to say, while I understand the big bolt pattern upgrade, you're gonna have a hard time making that car "look" better then it does right now. :thumbrig:
I agree finding draglites used would be the easiest now days, especially the 15x8's. The 6" fronts would be the most difficult. If you do go that way, just make sure whatever you find has a "offset" that works for you.
As far as wheels in general, while I can't give you exact weights on most, my rule of thumb has always been to stay with a "spun or forged" wheel for weight savings. 30/40% less then steel wouldn't be out of the question. Obviously steel wheels are normally the heaviest, but many "cast" aluminum units (slots / Am. Torque Thrusts, etc.) in most cases, are only slightly lighter then steel for a given size. And I'd put the SS Cragar in that same ballpark.
Not applicable here, but I always considered weight in my tire selections also. But that was a little easier in the 70's/80's. :)
