what are these for.

If you want a trouble-free way to mount a Sanden compressor onto your slant 6, get one of Charlie's bracket sets. I got one and it is perfect. With his bracket set you can use Mopar's original A/C pulley which is installed onto the backside of the balancer, between the balancer and the timing chain cover. It is necessary to find a salvage slant 6 with factory air in order to get the pulley, but well worth it. Charlie's set beats all others in my opinion.