While the post isn't 8" specific, the title is enticing. So I'll throw this out for anyone interested. I believe only the 3.00, 3.40 and 3.55 were available for the 8" rearend. Some of the ratios seem to cross over between the 6-3/4" and the 8" (3.40 seemingly one of them).
Every time I go to Pick A Part (monthly - Sun Valley, CA) I check the 8" rears. The majority sadly have the center sections already pulled. There is one guy who at a minimum goes through weekly and pulls them all. Virtually all are 3.00 and a few 3.55. When I did my turbo swap I opted for the 3.00 thinking the Pinto was lighter than the Turbo Coupe and the 13" or 14" tires would work well. Ahhh..., not so much.
Ideally I think 3.25 would be best with shorter 13"-14" tires. But that ratio is limited to only a few older Fords. Otherwise it is the price of aftermarket gears and setup. So my quest is now for 3.40 as a compromise. If your running 16" tires you might get away with 3.55. Please note these ratios are referenced to daily driving.
Tom