the 2 inch bar is .25 thick, so 1.5 i.d. when i first built them i only had one bar and none of the lower stuff. the bars are so long that i could grab onto them and shake them 1-2 in back and forth. the bushings are super hard, the sleve is very tight, and the bolts fit perfect in the bushing sleve. no play there. i could make spacers no problem for the heims. the heims i got use a 1 inch bolt, and some of my tubing is 1.5 o.d. .25 wall, thus 1in i.d.. great for spacers. its what i used on my rock buggy i am building, and they worked great.