dmkustoms
+1y
What if you run a straight edge across the cab from rocker to rocker, then measure from the floor of the cab to the straight edge roughly where the frame runs, that would tell you how much space you have for framerail if you are doing a SFBD. Thats how I have checked for clearance on a couple truck cabs that were off the frames. If its less than 3 inches of clearance, i would plan on doing a mild channel though.