[patty442]

Nice discussion. I love you guys. I wish I had seen this earlier and saved all the hostile statements back and forth and offened egos These are the facts. FACTS. The bolts used originally by the AC factory, where the comp style filler was absolutely installed, were BSF hex bolts, period. My brother was at A.C. in 1967 at the parts counter at A.C. following my orders to get three complete Comp fillers, necks and all attaching hardware, for the car that I eventually going to own. I have them today 2013. Shelby, when the cars were painted, changed the bolts to aircraft surplus American fine thread low height indented thinned head bolts. He did not machine anything thinner. They came that way and he selected them that way. The bolts he used have a spherical circular depression in the thinned head with a thin AN washer added to protect the underlying aluminum flang. No stainless steel, machined, phillips anything. Period. There is a call out number on the head that indentifies the manufacturer, type of O.D. fit and basic thread size. No length call out on the head data. I'll give you all a hint, the company was in walking distance of the Shelby factory. Imagine that. Hope this helps.