NOTE: Installation onto the lightened-weight crossmember used on 1981-1984 K10 trucks will require one-less bolt/nut to be used than on 1973-1980 crossmembers and also require the far-left hole on the rear flange of the crossmember to be drilled-out larger to 3/8" diameter. NOTE: If the Hooker Blackheart BHS5112 K10 crossmember brace is also being installed, install it now onto the bottom of the crossmember. If used, reinstall the factory transfer case skid plate onto the crossmember underneath the Hooker Blackheart brace using the same holes that were previously used to attach it. Longer bolts may need to be acquired by the user for this purpose.