2000 Silverado 4.3 with LQ9 6.0 swap harness issues..

First time poster, so here we go.. So i'm using a LQ9 motor, trans, harness, fuel lines, etc out of a 2003 Escalade to go in my 2000 Silverado 4.3.. Engine and trans harness plugged into the fuse block just fine, but there are 2 plugs under the fuse block from the Escalade harness, that do not match 2 plugs with the original truck harness(both 8 pin i believe).. Both plugs do not go through the fuse block, and should simply plug into one another, but are different plugs. Just curious if anyone has came across this? Other sites and forums do not mention this issue... Thanks