I found the number 3836340 embossed on the block just in front of the distributor. According to inliners.org that should make the engine a 1955-57 261. My friend has offered the engine to me, so that I can replace the 216 that I have in my 1953 1/2 ton. I was concerned that since there is no external oil filter, does that mean oil was not circulating the engine components properly? Or does the external oil filter only circulate 20% of the engines oil? He ran his truck with this engine for eight years until about two years ago. He plans on replacing this engine with a 350. I'll also check the head numbers tomorrow, when we try to start it up again. Personally, I don't think he has any idea, when he says the engine has oil slings.
