I had about 25k trouble-free miles on the QA1 K-member before it came out for my mod motor swap, There wasn't any signs of cracking or anything like that but looking back I probably wouldn't sacrifice the strength of the stock k for the little difference in weight it are up for. As far as fitment, according to MM the 79-95 mounting bolts are the same but the 96-04's have slightly different locations for the 4 short rear-most bolts, so you would have to do some grinding on the k-member if you were going to use MM. I believe QA1 elongates the rear-most holes to be universal to 79-04.