Pictures please. See the Animated banner at the top of this page? There you will find factory assembly manuals and shop manuals for your truck. (Very helpful) If you have a picture of the engine we could tell ya if it's a 235 or the original 216. Easiest way to tell is the valve cover. If it's got two bolts holding it down in the center of the valve cover, it's a 216. Also If the side plate (sheetmetal) that covers the pushrods goes above the spark plugs, it's a 216. There is also a date code right at the top of the starter. Example: E167 This would decode as E= May, 16= 16th of the month, 7= last digit of the year or 1957 if it's a 235. Lot's of good stuff can be found using the search feature on this forum. Good luck.
