for example, i have 1 hot rod, my sivberado with a single stage system, and 3, my TA, My Bmer and my Lesabre( a 4 dr 1978 w/ a 403 Olds that it CAME with) all of which have dual stage systems....and MSD auto retard ignition systems all, 7al2 on the TA, 7al 3 on the Bmer, digital 6 on the silverado and the lesabre
I treat it like American Express, never leave home without it in either case.