"Stove Bolts" are round head machine screws with square nuts, used to assemble wood or coal burning cast iron heating stoves. When Chevy started producing inline sixes, they chose to use these commonly available hardware items to hold the sheet metal parts on such as oil pans, valve covers, pushrod covers, etc. Later, they went to a screw with a flattened head (pan head), but with the same 1/4-20 standard thread. Using standard hardware items instead of producing a dedicated bolt was in line with Chevy's "baby chicken" approach to producing the engines- - - -"Cheep- - - -Cheep- - - -Cheep!"
Jerry
