b'Bump Steer Components pro Bump steer BoLt kits Track-Star Bump Steer Kits For Race, Track & Autocross Cars where we are NOT using the Factory OEM spindle, we use steering arms that have a 5/8 bore instead of a tie rod taper. Many Racers will take OEM & aftermarket spindles with tapers in the arms & straight bore them to 5/8 to utilize this stronger package.I use the word bore intentionally, as we do this in a mill. Doing it with a hand held drill & drill bit can result in the hole not being truly round, precise in size or straight. You can do it, but this is NOT an area for being sloppy.It may look like just a bolt & hardware, but this is the best method & high grade hardware. We utilize 12-Point bolts that are rated at 170 KSI. (Grade 8 is 150 KSI). They are 5/8 by whatever length you may need, up to 5.00. The flange under the 12-point head is the same diameter as spacers & the flat surface on the rod end ball. So, the 12-Point head goes in from the bottom like you see here. This also provides more clearance from the wheel.The small OD steel spacers would dig into the bottom of aluminum steering arms & probably twist. But we provide a special gold zinc coated, .250 tall, chromoly, tapered spacer (red circle) to spread the load & protect the steering arm.Use the Large OD SAE washer (purple circle) & the regular nuts (green circle) we supply for taking on & off many times while adjusting your bump steer. Use the full height Aircraft Nylock Nuts (blue circle) for final assembly.Quick Tips: If we want more Toe-Out in dive: Raise pivot at rack or inner tie rod end at centerlink, or lower the outer tie rod end with spacers If we want less Toe-Out in dive: Lower pivot at rack or inner tie rod end at centerlink, or raise the outer tie rod end with spacersThe standard kit includes 3.50 12-point bolts & an assortment of spacers & shims to dial in your bump steer.If you find your car need longer bolts & more spacers, we have 4.00, 4.50 & 5.00 kits we can send you at no charge. The 4.00 & 4.50 kits replace the .250 tall tapered spacers with .625 tall tapered spacers. If you need over 2 of spacer, our 5 kit includes two tapered steel spacers 2.00 tall, instead of .250 tall tapered spacers, plus all the regular shims & smaller spacers. Again, no extra charge if you need either of the longer kits. Lastly, dont sweat the ratio in the steering box being 12.7-1 or 14-1. AllRSRT Spindles utilize shorter steering arms that are slotted. Your kit comes with 0, .250 & .500 Offset Slugs for a Steering Arm Range of4.25-5.25 in 5 steps. The effective arm length is in the 4.9 to 5.9 range when we rotate the spindle to the target caster we run. You can fine tune the slugs to make the steering moderately quick to super quick to suit your personal preferences.393'