Mud Flaps/Rock Protection for '72 4 x 4 Stepside

[rpatowers]

I drive on gravel roads frequently and the rocks kick up and chip the paint along the bottom of the cab and on the front of the bed step. I purchased 'splash guards' but they don't fit well on my '72 (the only ones available are for later model trucks) and do not stop all of the rocks (they only protect the area immediately behind them).

Can anyone recommend mud flaps that will fit my truck and stop the rocks from eating my paint?

Can anyone recommend any other means of stopping the rocks?

Thanks, All!!