[xpickup]

nickp51chevy, The splash aprons were done on slip rolls and then have a 1" 90 degree bend on the bottom of them. That way you can bolt it to the top of the running board. If you don't have a slip roll it can be done on a brake. Mark your sheet metal on both ends every 1/4" were your radius will be and bend a little at each mark till you get the right radius. I made a radius gage to check it as I go.
The running board I have a 1" back bend on the bottom then I think it is 1 3/4" high and then what ever the distance back. The truck I am working on has 3" wider fender in the back so the running board is wider in the back. Next I bent the upright pieces. I have a 1" bend at the top then whatever the distance tto the running board then another 1" bend at the bottom. So it looks like a channel. On the bottom of the channel I unibitted holes every 3" and they are 3/8" to plug weld channel to running board and also stitch welded on back side of the runnig board. The channel isn't all one piece and isn't staight. Under the cab is 1/2" lower than the area where the splash apron is. The running boards were the left over pieces from the making the bed sides. They were longer than they need to be but that was good that way you have room for error for cutting the radius for the fenders. I fit it to the front and back fenders. I then welded in a piece of sheet metal for the ends so that it bolts to the fenders. If you need any pictures let me know and I'll post them.