I'm not sure about that year, but most older trucks had parts made from 19 gauge sheet steel. That is .0418 thickness. At least that is what I have measured on my stock 1958, I checked various parts. Most all the parts supply places use either or both Counterpart and Dynacorn sheet metal parts so far the gauge checks pretty close. It seems to vary from 19 to 17 gauge, and the smaller the gauge the thicker the metal. I'm sure the 66 is 19 gauge as well, you will need a micrometer or good machinist calipers to check it. For just getting the sheet metal in flat sheets, one of the outfits I think LMC sells it, and then of course a metal supply place in your area.
I would not buy mail order for sheet metal parts, find a supplyer that is close so you can pick and choose, look for flaws etc.
Last edited by Truckrolet; 04/02/2011 5:33 PM.
