All 1981 and later slant sixes were factory equipped with hydraulic lifters, which is why your kit gave you a hydraulic lifter cam. Either your engine isn't actually an early 80's slant, or someone converted to solid lifters at some point.

Slant six blocks were never cross drilled for hydraulic lifters. When hydraulic cams became necessary to reduce emissions levels, a "Canadian engineer at the Windsor Plant working with the tappet supplier came up with the idea of feeding oil to the tappets by transferring the oil down through the hollow push rods from the cylinder heads where there already was oil available under pressure for lubricating the valve train." Dec/Winter 1992 issue of the Slant 6 News: History of the Slant Six engine, Part 2.

You'll note that although oiling through the pushrods is also used by SBC/AMC/Mopar Magums (and others), they all oil the rockers from the lifters instead of oiling the lifters from the rockers as the hydraulic-cammed slant six does.