Next, we noticed the lower balljoints are different. On the A spindle, the balljoint is integral to the steering arms, while the B spindle has a balljoint in the control arm, having just a tapered hole in the steering arm. The late A-Body lower balljoint is actually used in '73-'76 A-Bodies, '70-'74 E-Bodies, and '62-'72 B-Bodies. They carry Moog PN K781 for left and K783 for right. These numbers can be crossed referenced at most any local auto parts store. The late B spindles do use the same mounting holes, so the solution is to use the A-spindle balljoint. The only hang-up is the attachment bolt length. The B spindles use a shorter bolt, so you'll need to get your own bolts. Use 5/8-inch by 18TPI by 2.5-inch-long grade 8 bolts. They're readily available at any fastener store. It's best to use squish-type lock nuts as well. If you prefer the OEM bolts, you can find them on any of the above-mentioned cars using the 781/783 balljoints.