Probably to help them not spin the tires as hard as they would with a closer LSA
I use to use Isky 590-616 solid lifter grind cams in my BB M.W. motors back in the mid 1970s, it was ground on a 104 LSA and I would installed it between 99 and 101 ILC
I like that cam a lot but isky took it out of their catalogs and made it a "custom grind"and wanted to charge $30.00 more for the "custom grind"
I quit buying direct from Isky as a "dealer" about that time and switch to become a dealer for Comp Cams, went faster too