The larger diameter bolts are start with the 2000 year models... Due to the axle changes for the Off-Road.
Remember when we swapped my lift from Greg's truck? He kept the control arms on his 99 because the bushing sleeves didn't fit.
If you can remove a bushing or sleeve from the ends of the control arms, then you could replace them with the correctly sized ones made out of steel tubing. shouldn't be too hard.