I just picked up this flatty. Need help identifying what type it may be. The heads have 81T on them which would be out of a 38 truck if I'm not mistaken. The number on the block is what is throwing me for a loop. It has 20 stamped on it. I have not seen anything that references that number. This is my first flathead so I need all the help I can get.
The heads on the motor are 39 to 42 truck. The block looks like a 39-40 unit but I can't be sure from the pictures you posted. The number 20 on the block is meaningless these days, any records from Ford that would have helped burned up with the Rotunda fire decades ago. We have a thread on there that will let you identify your block: http://jalopyjournal.com/forum/threads/ford-flathead-block-identification.594463/ Post more pictures including intake manifold surface and oil pan rail. If you are pulling the head then the center water holes in the deck.
Those heads were used in a number of years and applications and of course heads are meaningless any way since they can be used on other years. Presumably, no 59 on bell. Look at sides of block...are there 2 raised ridges on each side leading down to pan rail, where they meet a freeze plug on the rail itself? If so, '38 or '39-40. If no ridges, is manifold on a sort of "raised" cast iron platform that looks almost like the manifold gasket? '41-2 or wartime. Crank nose...can't see enough...if pulley has a short tube running forward from its flat front, and it looks like crank sticks out from casting about an inch, '39-up. If there is no protrusion past the flat and it looks like end of crank is about flush with casting, oddball '38 only engine. Intake looks like '39 up, but ofcourse is interchangeable. If '39 up, 221 and 239 are visually indistinguishable until you pull heads and inspect type of water holes...221's can be bored to 239, so you meed to ID by the holes. Look for a 1/4" high "99" stamped (not cast) at right front of manifold face of block...some '39-40 239's are marked thus.
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