Ifyou can't get an answer here is a link to buy a shop manual for a 1938: http://images.google.com/imgres?imgurl=http://www.lloydsautolit.com/products/stdImages/4058.jpeg&imgrefurl=http://www.lloydsautolit.com/Items/1938%2520Chevroletcar%2520Chevytruck%2520Shop%2520Manual/3844.html&usg=__F0ajm7iaUbfc48MMV5bjQaau68Q=&h=422&w=350&sz=18&hl=en&start=21&um=1&tbnid=UF0s20NC5_XZMM:&tbnh=126&tbnw=105&prev=/images%3Fq%3D1938%2Bchevy%2Btruck%26hl%3Den%26rls%3Dcom.microsoft:en-us:IE-SearchBox%26rlz%3D1I7GGIT_en%26sa%3DX%26um%3D1

But I'd figure somebody on here has the answer you want. Good luck.