First question I have is what are you using the vehicle for? If it going to be used off road more often than onn road or about 50/50 and you dont want to blow sidewalls as often, then go with the 12.5 on the 8" rim. They work just fine. I know of plenty of people that have this setup and have yet to see an issue with abnormal wear. If you are going to be doing more city/freeway driving and only take the truck on the occasional dirt road, then go with the 10" rim.. Better road handeling, albeit hardly noticable, is about all that you could expect Your choice. I would deffinatley recomend the 8" for any type of semi-serious off road use tho.
'78 Chevy 1 ton Stepside RockCrawler
468 BB, SM465, NP205
D60 front, GM 14Bolt rear w/ Detroit
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