When I had the stock K-frame I got 2 small axle U-bolts (2 1/2"x 1/2" or so). I drilled 2 holes on the each side edge of the K, then put the U-bolts up through the 2 holes and used 4 nuts to lock the U-bolt in place facing down. Gave me something for the straps to hook to that was solid. Quick fix for stock K frame cars

<Edit> since I never took a pic of where I put the U-bolts, I tried to show it in this pic with the black dots *** see attached ***