I got my AFCO coil over shocks from Speedway Motors.com, 106-1665 16 series, small threaded, twin tube shock-6 inch-comp. 5/5 rebound.
AFCO springs, coil over, 1-7/8" inside diam. rate, 10" Part no 291???-1. You have to figure out the weight you want to support. I got the 106291-250# pound rated springs on my Dom, I have a Corvair engine, which weighs 225 pounds. You also have to purchase a coil over kit, AFCO R- series kit 106 (20123).