You can do it but the wheel willl stick out about 2" on each side. even with offset wheels they still stick out. its almost a boltin deal. You need some 1/2" spacers for each side and then drill the holes for the cross member. I don't think GMC and Chevy were different in that year but some one else may chime in on that.
its an relatively inexpensie swap but as I said the wheel will stick out some. You could wide the front fenders and that would take care of it.
Here is the link.
http://53truck.ez15loan.com/ifs.php