I recently purchased a 1970's Chaparral 6x6 to restore and all of the 3-lug Firestone 60" circumference Max Floatation tires are bad. I assume I will have to go to 8" rims and the 3-lug to 4-lug adapters, but what is the best rim offset and tire size should I get to replace the original tires. Has anyone had any experience with this?