73 kframe on 72 abody

I need to squeeze the rails if that is the case. I was able to straighten the front frame rails where the K-frame bolts up using a steel I-beem (custom made)and the original bolt. so front frame rails now look good and k-frame bolts in front holes no problem. Just the back two holes are about 1/16 two tight.(both sides) Other words, the frame rails or the new k-frame rear holes are centered about 1/16. The frame rails do not look bent now. Front hole are larger than the rear. So why not open the rear holes up a little? I maybe confused. Thanks all. Still thinking on this one.