Hoosier and M/T do slicks in 26x8 & 26x8.5. You are limited if you don't want to massage the wheel openings.

I would be hesitant to put a radial on it without do any other changes. A stock 8.75 is going to be short lived. Some sort of adjustment is needed in the bellhousing. A bias tire would be a better choice if you don't want to go there. Again, the 8.75 and the driveshaft need some attention or upgrades.

Talk to stick shift stocker guys. Plenty of good Mopar stockers in the midwest.