The 3/4 ton 8-lug rear should the same as the 1 ton front. The question really lies in: "Will it fit over the brakes?"
I know a 16" rim would be a tight fit for mine (original drums), thus I have 17's.
IIRC, GM didn't offer 15" rims for 8-lug axles, at least on the Advance Design trucks. What year truck are you looking at?
