box sides on these old trucks are flat, (without the fenders on them). i got a shop to break new sides out of 16 gauge steel, after spot welding the new steak pockets on, steel pipe along the top to simulate the factory roll, and bolting on fiberglass fenders (much frustration) the side are no longer straight. I am not a body guy, i am a mechanic by trade, lol. I am wondering how flat or straight these side actualy end up on most trucks? It s so hard to work with a flat surface! After sliding 4 foot level across them i see waves up to a 1/4 inch. Is this normal? lol. Any input would be greatly appreciated, thanks