You Lug nut pattern is 5 / 4.75 with a backspace is 6" same as the Corvette and Camaro rims. I have a set of 16" IROC rims on my 4WD 96 Jimmy and a set of 16" C5 Corvette rims on my son's 4WD 96 Blazer without the use of spacers.
Good luck and hope this helps, keep us posted on your new rims.