I get asked almost daily,... either on the board or via PM, about the correct "offset", or "backspacing" for wheels, for these old trucks.
Since my normal answer is to, "Measure your truck, yourself",... I'm going to use this thread to post any info or store any videos that explain the process.
Here's one for a '74 nova, that I found today.
The length of the video is kinda long, but it covers all the details.