Auto body repair & detailing: rocker panels, kids truck, rocker panels

Question
i am helping my son rebuild his 1976 chev 1/2 ton, we have to replace the rocker panels so i went ahead and bought after market outer rockers inner rockers and a new floor pan the problem is the outer rocker looks normal the inner well that is another story looks like it can fit on many ways and the floor well i thought it would be just a flat piece of metal but there is a 3 inch flange on it that faces towards the ground..... does anyone have any pictures or discription on how this is supposed to go together? would really be appreciated would hate to screw up my kids truck and yes they are all weld in parts

Answer
Wes sorry im not aware of any books that show this kind of repair.can you tell by looking at the old one how it was welded in most of the you have to make a the 3 inch flange and spot weld it to the rocker inners first before you weld the floor in,let me see if i can find a truck so i can take some pics so i can see if i can help you a little better