I can't remember the exact model, but I do know that Kennedy sells the right thing. I bought some a few years ago. Sorry, I know that doesn't completely help. The "HD" part sounds familiar, though. Although now that I think about it, aren't there only two models? The HD and some type of softer-riding model? If that's the case then I definitely got the HD.
1998 K2500 Suburban 6.5L TD 3.73 rear, Ron Schoolcraft 18:1, Kennedy ECM & IC, Timing gears, Splayed main caps, 3.5" Kennedy Exhuast/No Cat, K&N Filter, Boost/Tranny Temp/EGT(Pre Turbo), Ceramic-coated Manifolds, 195 Stat's, 265/75's (VSSB Adjusted) 7,000lbs (on a scale) Remote Mount Oil Filter, Remote Oil Pressure Sensor